Dissertations / Theses on the topic 'Fiscal variables'

This paper empirically assesses determinants of countries' fiscal rules suggested by the political science, sociology, and economics literature. We find several of these variables to be related to the stringency of fiscal rules, providing indirect evidence for the relevance of governments' deficit bias. These determinants may also serve as instruments in models with (endogenous) fiscal rules as explanatory variable.

2008-2009
This thesis investigates the macroeconomics e ects of scal policy from a theoretical and empirical perspective. The rst part of the thesis surveys recent theoretical and empirical studies in the related literature. The analysis shows that while consensus has emerged on the positive e ect that an expansionary scal policy has on output and hours worked, no widespread consensus exists on the e ects that such a policy delivers to private consumption, real wages and investment. While in standard RBC models the negative wealth e ect on households' lifetime resource constraint prevails, in more or less articulated new-Keynesian models a crowding-in e ect of consumption and an increase in wages is made possible also under plausible calibrations. While early empirical contributions gave credit to the standard neoclassical predictions, the most recent econometric applications, generally making use of structural VARs, have supported and in many cases have inspired the latest new-Keynesian claims. Next, this work applies graphical modelling theory to identify scal policy shocks in SVAR models of the US economy. Unlike other econometric approaches { which achieve identi cation by relying on potentially contentious a priori assumptions { graphical modelling is a data based tool. Our results are in line with Keynesian theoretical models, being also quantitatively similar to those obtained in the recent SVAR literature a la Blanchard and Perotti (2002), and contrast with neoclassical real business cycle predictions. Stability checks con rm that our ndings are not driven by sample selection. In its nal part, the thesis empirically explores the information content of a large set of scal indicators for US real output growth and in ation. We provide evidence that uctuations in certain scal variables contain valuable information to predict uctuations in output and prices. The distinction between federal and state-local scal indicators yields useful insights and helps de ne a new set of stylized facts for US macroeconomic conditions. First, we nd that variations in state-local indirect taxes as well as state government surplus or de cit help predict output growth. Next, the federal counterparts of these indicators contain valuable information for in ation. Finally, state-local expenditures help predict US in ation. A set of formal and informal stability tests con rm that these relationships are stable. The scal indicators in questions are also among theones that yield the best in-sample and out-of-sample performances.
VIII n.s.

This study had two purposes: (1) to formulate and test for sensitivity and comparability of Resource variables based on data collected across multiple sites; (2) to formulate and test for sensitivity and comparability of Fiscal variables based upon data collected across multiple sites. This exploratory descriptive study utilized data collected during the Differentiated Group Professional Practice project. Global analysis was utilized in creation of nurse Resource and Fiscal variables. Correlational statistics were utilized to evaluate performance of Resource and Fiscal variables within the project model. The Professional Practice index of Autonomy demonstrated a positive relationship with the nurse Resource variables of Retention and Stability. Increases in Professional Practice indices demonstrated negative relationships with Fiscal variables. Satisfaction demonstrated relationship to Resource or Fiscal variables.

Cette thèse analyse la dynamique spatiale et temporelle de la capitalisation des variables fiscales locales (impôts et dépenses publiques) dans les valeurs immobilières des communes du Canton de Zurich. Bien que la littérature ait maintes fois mis en évidence le phénomène de capitalisation, la question de son ampleur ainsi que son interprétation reste ouverte. Bon nombre d'analyses interprètent la capitalisation comme un test de l'hypothèse de Tiebout et associe sa présence à une fourniture Pareto-optimale des biens publics. Cependant, une partie de la littérature considère que la présence de capitalisation signifie au contraire que les collectivités locales n'ont pas atteint un équilibre de Tiebout. Par ailleurs, cette thèse contribue au débat sur la persistance de la capitalisation en estimant le changement du taux de capitalisation des variables fiscales en réaction à des différences d'offre immobilière selon la situation de la commune dans l'agglomération Zurichoise et à travers le temps. Ainsi, le taux de capitalisation devrait être plus faible dans les collectivités disposant d'une plus grande quantité de terre disponible et devrait décroître à travers le temps, à mesure que l'offre immobilière s'ajuste par le biais de nouvelles constructions dans les communes attractives. Les résultats indiquent cependant à l'inverse de la théorie une persistance de la capitalisation fiscale à la fois sur l'ensemble de l'agglomération Zurichoise et à travers le temps. Ces résultats soulignent l'importance de l'utilisation du zonage par les autorités locales, qui rendent rigides l'offre immobilière et favorise le phénomène de capitalisation
This thesis analyzes the dynamic of fiscal capitalization across space and over time in the Canton of Zurich. While the literature provides a profusion of evidence on capitalization, there is still a controversy on the extent to which local fiscal variables capitalize into house values and on the appropriate interpretation one must have with respect to the Tiebout hypothesis. The outcome of a significiant degree of tax and public expenditures capitalization is often interpreted as a test of the Tiebout hypothesis and associated with a Pareto efficient provision of local public goods. Some authors criticize this view and argue that capitalization of local fiscal variables does not describe a full Tiebout equilibrium. Fiscal capitalization results from scarcity of land that prevents households from moving toward communities with favorable tax-expenditure packages. While it has been raised in the 70's, the question of the persistence of capitalization has not received a definitive answer. This thesis aims to contribute to this debate. We estimate the change of the capitalization rate in response to housing supply differences across space and over time. The capitalization rate should be lower in communities with higher level of available land for construction and should decrease over time, as new constructions occur in attractive communities. Overall, our estimation seems to indicate a persistence of tax and public expenditures capitalization both across space and over time. These results are consistent with the intensive use of zoning regulations at the local level

The object of this dissertation is the evaluation of the effectiveness of fiscal policy as stabilizing tools in the Baltic countries. The aim of the research is to evaluate the effects of tax and fiscal policies on such Lithuanian, Latvian and Estonian macroeconomic variables as gross domestic product, employment, foreign direct investment and interest rates. Structural Vector Auto Regressive mode (SVAR) has been employed for the analysis. Results of the research suggest that tax shocks may have different effects in different countries: labour tax increases adversely affect output and employment in all economies. It is only Lithuania where indirect tax increases negatively affect output while in Latvia and Estonia indirect tax shocks effects are positive. Persistent results of the negative corporate income tax effects on macroeconomic variables were obtained only in Lithuania as well, results in Latvia and Estonia vary depending on the SVAR variable composition. The results show that the increase in government spending leads to GDP, employment and foreign direct investment decline in Estonia and Lithuania, while in Latvia the negative impact is less significant. On the other hand, public investment has a positive impact on macroeconomic variables in all three economies. Interest rates are relatively insensitive to fiscal shocks in all Baltic countries, and this may be explained by the high degree of economic openness and dependence on global market fluctuations.
Disertacijoje tiriama fiskalinės politikos įtaka Lietuvos, Latvijos ir Estijos makroekonominiam stabilumui. Disertacijos tikslas – nustatyti Baltijos šalių mokesčių ir fiskalinės politikos įtaką ekonominiams procesams ir kiekybiškai įvertinti fiskalinės politikos priemonių poveikį makroekonominiams rodikliams. Šiame darbe buvo tirti svarbiausių fiskalinės politikos priemonių – pagrindinių mokesčių, valdžios sektoriaus investicijų ir visų išlaidų poveikis BVP, užimtiesiems, investicijoms ir palūkanų normoms. Pasitelkus vieną populiariausių fiskalinės politikos efektams tirti taikomų metodų – struktūrinius vektorinius autoregresinius modelius (SVAR) – buvo prieita prie tokių išvadų: skirtingų mokesčių šokai nevienodai veikia Baltijos šalių makroekonominius rodiklius. Darbo mokesčių didinimas neigiamai veikia BVP ir užimtumą visose ekonomikose; bet netiesioginių mokesčių didinimas teigiamai veikia BVP Latvijoje ir Estijoje, ir tik Lietuvoje poveikis yra neigiamas. Tik Lietuvoje buvo gauti stabilūs rezultatai apie neigiamą pelno mokesčių poveikį ekonomikai. Latvijoje ir Estijoje poveikio efektai varijuoja priklausomai nuo SVAR modelio kintamųjų sudėties. Rezultatai rodo, kad valdžios sektoriaus išlaidų didinimas lemia BVP, užimtumo ir tiesioginių investicijų mažėjimą Lietuvoje ir Estijoje. Latvijoje neigiama poveikio įtaka yra mažiau reikšminga. Kita vertus, valdžios sektoriaus investicijos turi teigiamą poveikį ekonomikos procesams visose trijose ekonomikose. Palūkanų normos... [toliau žr. visą tekstą]

El presente trabajo de suficiencia profesional tiene como objetivo evaluar las posiciones tributarias y establecer aquella cuya exposición de motivos se encuentre sustentada en la legislación fiscal vigente, y respalde a las empresas de la industria de alimentos ante una posible fiscalización de la Administración Tributaria (Sunat), en la cual se cuestione la deducción de la depreciación de maquinarias y equipos, que por adopción NIIF sufrieron una disminución en sus costos históricos. Este hecho genera perjuicios económicos de origen tributario a las empresas del país, en especial a las empresas de la industria de alimentos, afectando su situación económica y fiscal en su calidad de contribuyentes, ya que en su mayoría estas maquinarias no han terminado de depreciarse. Por tal razón, la investigación se argumenta en que, si las empresas se encuentran respaldadas con una posición tributaria sustentada en la normativa fiscal peruana se podrán deducir íntegramente la depreciación tributaria de la maquinaria devaluada, en particular las empresas de la industria de alimentos, evitando así perjuicios económicos en el cumplimiento de sus obligaciones tributarias. Metodológicamente la investigación se basó en entrevistas realizadas con la finalidad de conocer las posiciones tributarias que existen en el mercado, y hacer un análisis de las mismas basándonos en la normativa tributaria. La muestra se compuso por directores y gerentes de impuestos de empresas de la industria de alimentos, firmas auditoras y estudios contables, que prestan servicios de asesoría tributaria en el Perú. Asimismo, los cálculos realizados correspondientes al activo fijo se basaron en informacion proporcionada por una importante empresa de la industria de alimentos que nos permitió cuantificar el impacto económico de las posiciones más representativas del mercado. Los resultados de la investigación demuestran que, la posición que te permite deducir la depreciación tributaria del costo histórico de la maquinaria y equipo devaluada por adopción NIIF, sería la que más se ajusta a la normativa jurídica tributaria vigente.
The present work of sufficiency professional has as objective assess them positions tax and establish that whose exhibition of motives is find sustained in the legislation tax existing, and support to the companies of the industry food before a possible control of the Administration tax (Sunat), which is in question the deduction of the depreciation of machinery and equipment, which suffered a decline in their historical costs by adopting IFRS. This made today could generate damages economic of origin tributary to the companies of the country, especially to the companies of the industry food, affecting your situation economic and fiscal in its quality of taxpayers, since most these machines have not finished to depreciate. By such reason, the research is argues in that, if the companies are backed with a position tax supported by Peruvian tax regulations may not be reduced completely devalued machinery tax depreciation, in particular the companies of the industry food, avoiding thus damages economic in the compliance of its obligations tax. Methodologically, the research was based on interviews conducted with the purpose of knowing the tax positions that exist in the market and make an analysis of them based on the tax legislation. The sample was composed by directors and managers of taxes from businesses in the food industry, firms audit and studies accounting, that lend services of advisory tax in the Peru. It was also quantified the economic impact of the most representative of the market positions resulting in that food companies would have a savings tax in case take the position to deduct tax depreciation the historical cost of machinery and equipment devalued by IFRS adoption. Therefore, this position would be that best fits the tax legal regulations, and which based on the results obtained and the analysis regulatory made propose a benefit tax to the taxpayer.
Trabajo de Suficiencia Profesional

Cette thèse s’intéresse d’une part aux effets macroéconomiques des régimes de change, et d’autre part, aux récentes évolutions sur la politique budgétaire et la décentralisation. La partie I met essentiellement l’accent sur l’interaction entre les régimes de change (RC) et la politique budgétaire, monétaire et fiscale. Tout d’abord, nous mettons en évidence que les RC peuvent avoir un effet stabilisateur sur la politique budgétaire (chapitre 1). Cependant, cet effet stabilisateur des RC n’est pas automatique mais dépendrait plutôt des conséquences d’une politique budgétaire laxiste. Le chapitre 2 s’intéresse quant à lui à la causalité entre RC et crises (bancaire/financière, de change et de dette) et remet en cause la vision bipolaire qui prétendait que les RC intermédiaires sont plus vulnérables aux crises que les solutions en coin (RC fixes/flexibles). Il ressort de notre analyse que les fondamentaux macroéconomiques (la volatilité du crédit au secteur privé, le financement du déficit, et le ratio dette sur PIB) jouent un rôle considérable. Le chapitre 3 met en évidence un lien entre les RC et la politique fiscale. Les pays à RC fixes montrent une plus grande dépendance aux recettes domestiques –telles que la TVA-, comparativement aux pays en change intermédiaires/flexibles pour compenser les pertes de recettes de seigneuriage (effet de substitution). De plus, ces pays avec RC fixes collectent plus de recettes domestiques en compensation de la perte de recettes douanières, suite à la libéralisation commerciale (effet de compétitivité). Dans les trois derniers chapitres (partie II), nous mettons le focus sur la politique budgétaire et les effets de la décentralisation. Le chapitre 4 révèle une relation non-linéaire entre la politique budgétaire et le cycle économique, qui dépend du niveau de la dette publique. Lorsque celle-ci dépasse un certain seuil (87%), la politique budgétaire perd toute propriété contra-cyclique. Nous montrons par ailleurs que l’effet disciplinaire ex-ante des règles budgétaires aide à restaurer la contra-cyclicité de la politique budgétaire. A travers le chapitre 5, nous montrons que la décentralisation budgétaire, dans un cadre politico-institutionnel sein et dépourvu de corruption, améliore l’offre de biens et services publics. Le chapitre 6 conclut que la décentralisation impacte positivement le solde structurel. Cependant une asymétrie entre la décentralisation des dépenses et celle des recettes accroit la dépendance des gouvernements locaux vis-à-vis du gouvernement central en termes de transferts, et amoindrirait considérablement à l’effet positif de la décentralisation
This thesis explored, in two parts, the macroeconomic impacts of exchange rate regimes (ERR), as well as the recent developments in fiscal policy and fiscal decentralization. Part I has reconsidered the role of ERR and its interplay with fiscal, monetary and tax policy. The first result that emerges (Chapter 1) is that fixed ERR can serve as a credible policy tool for stabilizing fiscal policy. However, this stabilizing effect is conditional upon the inter-temporal distribution of the costs of loose fiscal policy. In assessing the linkage between ERR and crises (banking/financial, currency and debt), Chapter 2 evidenced that the bipolar view is no longer valid, and that, crisis proneness rather depends on the macroeconomic fundamentals (the volatility of private sector credit, the deficit-financing mechanism, and the debt-to-GDP ratio). In Chapter 3, we unveiled a strong relationship between ERR and tax policy. Countries with pegged regimes have greater reliance on domestic taxation -such as the VAT- to make up for the loss of seigniorage revenue (substitution effect). Moreover, peggers tend to collect more VAT revenue to offset the shortfall in cross border taxes following the trade liberalization reform (competitiveness effect). Part II discussed the cyclical response of fiscal policy in high debt periods, and focused on fiscal decentralization issues. In Chapter 4, we showed that the reaction of fiscal policy to the business cycle is non-linear and conditional to the level of public debt. When the debt-to-GDP ratio goes beyond a certain threshold (87%), fiscal policy loses its counter-cyclical properties. Further, we highlighted that carefully-designed fiscal rules help maintaining counter-cyclicality through an ex ante disciplinary effect. Chapters 5 and 6 analyzed the impact of fiscal decentralization on the efficiency of public service delivery and fiscal policy performance, respectively. Chapter 5 revealed that a sufficient level of expenditure decentralization, coupled with revenue decentralization, improves the efficiency of public service delivery. However, the political and institutional environment is critical for reaping decentralization-led benefits. Lastly, Chapter 6 concluded that fiscal decentralization has destabilizing effect by reducing the counter-cyclicality of fiscal policy. In addition, we found that decentralization strengthens the structural fiscal balance; however, vertical fiscal imbalances reduce the benefits of decentralization. It is therefore critical to limit asymmetries between expenditure and revenue decentralization, so as to reduce the transfer-dependency of local governments to the central level, and thus prevent decentralization from weakening the fiscal stance at the general government level

Decentralisation, meaning the delegation of responsibilities from central to lower government levels is generally assumed to improve the delivery of local public services. The theoretical assumption is that local authorities are encouraged by decentralisation to behave in a more accountable and entrepreneurial fashion. At the same time, accountability and (public) entrepreneurship are distinct concepts and may even be considered to involve conflicting behaviours. Therefore, decentralisation outcomes may vary depending on which behavioural pattern predominates. Previous research has focused on using large data sets to examine the impact of decentralisation on outcomes such as economic growth, disparities, poverty reduction and government performance. But there is also a need to better understand how decentralisation, and specifically fiscal decentralisation, may promote accountability and public entrepreneurship in specific settings. To contribute to closing this gap, this dissertation examines both fiscal decentralisation policies and contemporaneous changes in political arrangements. It identifies the incentives these changes create for Mexican local authorities to behave in more accountable and entrepreneurial ways and which may lead to differences in government performance. The study focuses on rural municipalities where achieving the predicted decentralisation outcomes is highly challenging. A mixed methods research design was used with two phases. In the first stage, the relationship between fiscal decentralization and changes in government accountability and entrepreneurship was investigated through statistical analysis based on fixed effects estimation using a sample of 505 rural municipalities. For that purpose a longitudinal dataset was developed, comprising municipal level information between the years 1990 and 2009, including indices for accountability and public entrepreneurship. Phase two involves multiple case studies of individual municipalities that were selected based on performance. The empirical evidence suggests that decentralisation policy has tended to work against accountability but has increased entrepreneurial behaviour in rural municipalities, highlighting the potential tension between the two. The extent to which these effects occur seems to depend on the particular fiscal arrangement. In addition, political competition seems to reinforce accountability and has an impact in entrepreneurship in a different way to the effects expected theoretically, though the effects are not as strong as with fiscal decentralisation. This study advances the public entrepreneurship literature and expands the understanding of fiscal decentralisation. Additionally, it provides suggestions for which policy arrangements are likely to promote accountability and entrepreneurial actions by public authorities.

Abstract of thesis submitted in partial fulfilment of the requirements for the Degree of Master of Commerce and Management Dynamics of macroeconomic variables in Fiji : a cointegrated VAR analysis By Shiu Raj Singh The objective of this study is to examine how macroeconomic variables of Fiji inter-relate with aggregate demand and co-determine one another using a vector autoregression (VAR) approach. This study did not use a prior theoretical framework but instead used economic justification for selection of variables. It was found that fiscal policy, which is generally used as a stabilisation tool, did not have a positive effect on real Gross Domestic Product (GDP) growth in the short term. Effects on GDP growth were positive over the long term but not statistically significant. Furthermore, expansionary fiscal policy caused inflationary pressures. Fiji has a fixed exchange rate regime, therefore, it was expected that the focus of monetary policy would be the maintenance of foreign reserves. It was, however, found that monetary expansion in the short term resulted in positive effects on real GDP growth and resulted in inflation. The long term effects of monetary policy on real GDP growth were negative, which are explained by the fixed exchange rate regime, endogenous determination of money supply by the central bank, an unsophisticated financial market and, perhaps, an incomplete transmission of the policy. Both merchandise trade and visitor arrivals growth were found to positively contribute to short term and long term economic growth. Political instability was found not to have significant direct effects on real GDP growth but caused a significant decline in visitor arrivals which then negatively affected economic growth in the short term.

Disertacijoje tiriama fiskalinės politikos įtaka Lietuvos, Latvijos ir Estijos makroekonominiam stabilumui. Disertacijos tikslas – nustatyti Baltijos šalių mokesčių ir fiskalinės politikos įtaką ekonominiams procesams ir kiekybiškai įvertinti fiskalinės politikos priemonių poveikį makroekonominiams rodikliams. Šiame darbe buvo tirti svarbiausių fiskalinės politikos priemonių – pagrindinių mokesčių, valdžios sektoriaus investicijų ir visų išlaidų poveikis BVP, užimtiesiems, investicijoms ir palūkanų normoms. Pasitelkus vieną populiariausių fiskalinės politikos efektams tirti taikomų metodų – struktūrinius vektorinius autoregresinius modelius (SVAR) – buvo prieita prie tokių išvadų: skirtingų mokesčių šokai nevienodai veikia Baltijos šalių makroekonominius rodiklius. Darbo mokesčių didinimas neigiamai veikia BVP ir užimtumą visose ekonomikose; bet netiesioginių mokesčių didinimas teigiamai veikia BVP Latvijoje ir Estijoje, ir tik Lietuvoje poveikis yra neigiamas. Tik Lietuvoje buvo gauti stabilūs rezultatai apie neigiamą pelno mokesčių poveikį ekonomikai. Latvijoje ir Estijoje poveikio efektai varijuoja priklausomai nuo SVAR modelio kintamųjų sudėties. Rezultatai rodo, kad valdžios sektoriaus išlaidų didinimas lemia BVP, užimtumo ir tiesioginių investicijų mažėjimą Lietuvoje ir Estijoje. Latvijoje neigiama poveikio įtaka yra mažiau reikšminga. Kita vertus, valdžios sektoriaus investicijos turi teigiamą poveikį ekonomikos procesams visose trijose ekonomikose. Palūkanų normos... [toliau žr. visą tekstą]
The object of this dissertation is the evaluation of the effectiveness of fiscal policy as stabilizing tools in the Baltic countries. The aim of the research is to evaluate the effects of tax and fiscal policies on such Lithuanian, Latvian and Estonian macroeconomic variables as gross domestic product, employment, foreign direct investment and interest rates. Structural Vector Auto Regressive model (SVAR) has been employed for the analysis. Results of the research suggest that tax shocks may have different effects in different countries: labour tax increases adversely affect output and employment in all economies. It is only Lithuania where indirect tax increases negatively affect output while in Latvia and Estonia indirect tax shocks effects are positive. Persistent results of the negative corporate income tax effects on macroeconomic variables were obtained only in Lithuania as well, results in Latvia and Estonia vary depending on the SVAR variable composition. The results show that the increase in government spending leads to GDP, employment and foreign direct investment decline in Estonia and Lithuania, while in Latvia the negative impact is less significant. On the other hand, government investment has a positive impact on macroeconomic variables in all three economies. Interest rates are relatively insensitive to fiscal shocks in all Baltic countries, and this may be explained by the high degree of economic openness and dependence on global market fluctuations.

Does the financial structure create any value for the firm? The fiscal system is one defect of the contract that may challenge the theory of neutrality of Modigliani and Miller. In the frame of reference of transaction costs, Scholes and Wolfson have evidenced the existence of an implicit fiscal cost creative of a differential and of fiscal arbitration opportunities. The multinational firm characterized by a valorization of the market and an ability to win differentials of taxation. The fiscal speculation stages three actors : the country that is the source of the income, the taxpayer country of residence, that share an income according to the internal neutralization system and bilateral double taxation conventions, and the firm that is able to minimize its global fiscal cost through organizational arbitration methods. In connection with a structure of internal financing of the foreign subsidiary and a policy of financial flow repatriation, the French firm searching a maximization of its value is driven to adopt a fiscal planning strategy. The procedure of the "triangulation" adopted for the analysis of data has enabled us to show financial behaviors of the French firms different from those of the American firms and in relevance to the territorial taxation system, validating the function of the fiscal variable that way
La structure financière est-elle créatrice de valeur pour la firme ? La fiscalité est l'une des imperfections du marché de nature à remettre en cause la théorie de neutralité de Modigliani Miller. Dans le cadre de référence de la théorie des couts de transaction, Scholes et Wolfson ont démontré l'existence d'un cout fiscal implicite créateur d'un différentiel et d'opportunités d'arbitrage fiscal. La firme multinationale se caractérise par une valorisation du marché et une capacité à capter des différentiels d'imposition. Le jeu fiscal met en scène trois acteurs : le pays source du revenu, le pays de résidence du contribuable qui se partagent un revenu en fonction de système de neutralisation interne et de conventions bilatérales de double imposition et la firme qui par des formes organisationnelles d'arbitrage a la capacité de minimiser son cout fiscal total. En relation avec une structure de financement interne de la filiale étrangère et une politique de rapatriement des flux financiers, la firme française dans la recherche d'une maximisation de sa valeur est conduite à adopter une stratégie de planification fiscale. La méthode de la triangulation adoptée pour l'analyse des données nous a permis de mettre en évidence des comportements financiers des firmes françaises différents des firmes américaines et en adéquation au système d'imposition territorial validant ainsi le rôle de la variable fiscale

In this PhD thesis we address the problem of characterizing quantum states and parameters of systems that are of particular interest for quantum technologies. In the first part we consider continuous variable systems and in particular Gaussian states; we address the estimation of quantities characterizing single-mode Gaussian states as the displacement and squeezing parameter and we study the improvement in the parameter estimation by introducing a Kerr nonlinearity. Moreover, we address the discrimination of noisy channels by means of Gaussian states as probe states considering two problems: the detection of a lossy channel against the alternative hypothesis of an ideal lossless channel and the discrimination of two Gaussian noisy channels. In the last part of the thesis, we consider the one dimensional quantum Ising model in a transverse magnetic field. We exploit the recent results about the geometric approach to quantum phase transitions to derive the optimal estimator of the coupling constant of the model at zero and finite temperature in both cases of few spins and in the thermodynamic limit. We also analyze the effects of temperature and the scaling properties of the estimator of the coupling constant. Finally, we consider the discrimination problem for two ground states or two thermal states of the model.

Come le imprese decidono di comporre la loro struttura finanziaria è un tema sul quale si dibatte ancora moltissimo, alla ricerca di una formula che possa mettere insieme tutti i fattori che influenzano tale scelta e che vada a determinare la soluzione ottima. La soluzione ancora non esiste anche se la letteratura offre una grande quantità di modelli che tentano di spiegare quali fattori e in che modo, incidono nella decisione del mix di debito, equity e fonti di finanziamento ibride, adatto a supportare le decisioni di investimento dell’impresa stessa in un’ottica di massimizzazione del valore. La questione è complessa: moltissime sono le determinanti che vanno ad influenzare la scelta, autonomamente ma anche integrandosi tra loro, sempre tenendo conto della specificità di ciascuna impresa. Lo scopo di tale elaborato è di analizzare come una specifica determinante, la componente fiscale, impatti sull'ammontare di debito contratto. Per fare ciò si procede attraverso un’analisi empirica a verificare in che modo la variabile fiscale, declinata sotto tre diversi aspetti (aliquota societaria, interessi passivi fiscalmente deducibili e disciplina fiscale degli ammortamenti), venga presa in considerazione dalle società italiane quotate, andando a verificare se e come un cambiamento della disciplina sia stato recepito dalle società in termini di quantità di debito bancario detenuto.

Around the world, strategies are put in place to facilitate the adoption of low-carbon technologies (LCT) on the household level, yet, individual decision-making is complex. Despite information about driver and barrier related to adoption decisions for specific LCTs is abundant, its usefulness for understanding household adoption decisions is limited, because studies lack theoretical coherence and results are fragmented. This thesis aims to develop a decision framework by deriving universal mechanisms governing household adoption behavior from literature. First, related theoretical concepts are merged to a theoretical decision framework. Following an inductive approach, explanatory variables utilized in studies on decision-making concerning exemplary LCTs are clustered to superordinate explanatory variables (SEV) in the framework structure. Focussing on behavioral studies only, key SEVs, their interrelations and dynamics are analysed and combined in a practical decision framework. In the framework, the expression of general dispositions in a decision unit, and the expression of LCT traits in a technology are combined to explain behavioral driver and barrier which are predictive of behavior. A construct of hypothesis proposes explicit effects of specific general dispositions and LCT traits on behavioral driver and barrier in a functional (personal-functional), normative (environmental) and symbolic (social interaction) dimension. From a practical viewpoint, the framework offers a starting point for consumer-specific intervention strategies directly targeting general dispositions or LCT traits to enhance drivers or reduce barriers for adoption. Yet it doesn’t offer explanations as to why decision units enter the decision process, and future confirmatory research is needed to empirically test the proposed decision framework.

In this PHD thesis, I address the study of the evolution of quantum correlations of continuous variable systems interacting with classical environments, portrayed by classical stochastic fields. In particular, the first goal is individuating the working regimes where a full quantum description of the system-environment interaction may be simulated with a stochastic approach. As a paradigmatic example, I consider quantum harmonic oscillators subject to phase diffusion and dissipation decoherence. My results show that the stochastic noise may take over the full quantum description of Markovian dephasing channels, while a stochastic approach to dissipation only works at a high temperature in the early stage of the dynamics. The second goal consists in better exploring the connection between the dynamics of correlations of the system, non-Markovianity and backflow of information. In many situations non-Markovianity cannot be proved but only revealed by means of appropriate witnesses, usually associated to backflow of information. My results show that stochastic phase diffusing and stochastic dissipative environments lead to non-Markovian dynamics, but their non-Markovianity stays unwitnessed unless revivals of correlations as nonclassicality, entanglement or discord are detected. This suggests that non-Markovianity sets the natural framework for revivals of correlations, but the true resource to obtain revivals is the backflow of information. The third goal consists in showing that effects of local or global noise on a bipartite system may easily be distinguished by means of standard laboratory techniques. Indeed, my results show that homodyne-detection-based schemes may discriminate the effects of a global stochastic noise affecting two probes from local perturbation, using as states of the probe “lab-friendly” states.

Squeezed states of light addressed in this Thesis have proved to be the most readily accessible optical fields with demonstrably quantum mechanical behaviour in the Continuous Variable regime and they are considered at the heart of Quantum Mechanics. They may be concretely applied in several research fields such as metrology and quantum information science, as well as enabling to investigate the properties of the quantum world. Since their first observation, considerable progresses have been made in their generation and detection techniques. The research activity presented in this Thesis is devoted to the development of an experimental setup based thereon. The heart of generation process is a sub-threshold Optical Parametric Oscillator whereas the detection system is based on Homodyne Detector. On this structural background, we implemented an electronic/optical apparatus whereby it is possible to generate different kinds of squeezed states on demand. This Thesis presents how these engineered generation/acquisition processes work. Besides, it features a miniaturized Homodyne detection system based on a waveguide beam splitter inscribed in a glass substrate by femtosecond laser writing technology. We demonstrate for the first time the possibility to use such a device to detect genuine nonclassical features of light.

Background Con il termine microbiota intestinale, si definisce la comunità microbica del tratto enterico, composta da trilioni di microorganismi in grado di svolgere funzioni essenziali per l’ospite: metaboliche, strutturali e di protezione. Il suo ruolo, nei meccanismi di salute e di prevenzione, è al centro dell’interesse medico. Ma le modalità con cui il microbiota può essere alterato a nostro favore, non sono ancora del tutto chiare. Evidenze sulla modulazione da parte della dieta sono sempre più attendibili, mentre il ruolo dell’attività fisica, è ancora da approfondire, con una letteratura basata principalmente sull’effetto dell’esercizio fisico negli animali. Scopo della ricerca Indagare la letteratura a supporto dell’efficacia dell’attività fisica come fattore in grado di alterare la composizione del microbiota intestinale nell’adulto sano. Materiali e metodi La ricerca è stata condotta nel periodo di tempo che va da maggio 2020 a settembre 2020, consultando i database Pubmed, PEDro e Cochrane. Le parole chiave utilizzate sono state Physical execise, Aerobic exercise, Physical activity, Cardiorespiratory fitness, Gut microbiota, Microbiome, Adult, Human, Probiotics e Diet, combinate con l’operatore booleano AND, OR e NOT. Sono stati inclusi studi primari e secondari, in lingua italiana o inglese, che valutassero l’alterazione della comunità microbiotica, in adulti sani, dopo aver svolto esercizio fisico. Risultati La ricerca in letteratura e l’analisi degli studi, attraverso i criteri di eleggibilità, hanno condotto all’individuazione di un RCT, un clinical trial e due case report. Conclusioni Gli studi analizzati riportano risultati incoraggianti, per quanto riguarda l’effetto dell’attività fisica nel modificare la comunità microbiotica. I limiti riscontrati in questa revisione, rendono però difficile interpretare i risultati in maniera oggettiva, in quanto appare impossibile escludere altri cofattori.

The Far-infrared Outgoing Radiation Understanding and Monitoring (FORUM) mission has been selected to be the Earth-Explorer 9 mission of the European Space Agency. The main instrument on board of FORUM is a Fourier Transform Interferometer measuring the outgoing longwave radiation from 100 to 1600 cm-1, designed to provide for the first time the spectrally resolved full emission spectrum of the Earth and the atmosphere. The far infrared (FIR) region below 600 cm-1 contains large part of the information on climatological key variables strongly driving the Earth Radiation Budget. This work investigates the information content of the FORUM synthetic radiances in a large set of atmospheric scenarios. First, the sensitivity of the acquired signal in the FIR is studied by analysing the derivatives of the spectrum with respect to water vapour concentration and surface emissivity. The precision on these variables is estimated from the inversion of synthetic FORUM measurements. We then have calculated the systematic contribution due to different systematic sources on these parameters. The uncertainties on water vapour spectroscopic data is a relevant source of systematic error, therefore we assessed the consistency of recent spectroscopic data by analysing the agreement between the simulations performed using different spectroscopic databases and the REFIR-PAD measurements over Teresina (Brazil). Finally, the airborne measurements of the Tropospheric Airborne Fourier Transform Spectrometer (TAFTS) have been analysed to retrieve water vapour VMR from 0 to 9 km. The quality of the obtained products has been estimated studying the consistency of the retrieved profiles with those evaluated by in-situ dropsondes and the Numerical Weather Prediction model, determining also the information gain on water vapour VMR in the upper troposphere due to the measurements in the FIR range.

Le prestazioni delle superfici aerodinamiche impiegate in applicazioni aeronautiche, sportive o energetiche, ricoprono un ruolo sempre più cruciale. Aumentare l’efficienza aerodinamica, per esempio delle pale di aerogeneratori o dei più classici aeromobili, può avere interessanti risvolti economici ed ambientali. In questa tesi vengono valutate, dal punto di vista sperimentale, due soluzioni differenti volte a migliorare le prestazioni e l’efficienza aerodinamica di profili e superfici alari. Il primo metodo rientra tra i sistemi di controllo dello strato limite di tipo passivo, e consiste nell’applicazione di “dimples” su un profilo laminare NACA 642014A. I dimples, letteralmente tradotti “fossette”, sono largamente impiegati nei corpi tozzi (palline da golf, caschi da ciclismo etc.), per ridurre la resistenza aerodinamica del corpo stesso ma molto meno frequenti su superfici aerodinamiche. Sono state condotte misure sperimentali nella galleria del vento ambientale dell’Università Politecnica delle Marche su due modelli 3D di NACA 642014A, con e senza dimples, con lo scopo di validare precedenti analisi CFD e valutare la capacità del dimple di ridurre l’estensione della bolla laminare e ridurre la resistenza aerodinamica su moderni profili alari. La seconda soluzione affrontata in questa tesi, consiste nel rendere deformabile una porzione dell’ala che prende quindi il nome di “morphing wing”. L’obiettivo è quello di modificare la geometria della superficie in questione durante l’utilizzo, variando i parametri relativi alla sua curvatura (camber); in questo modo essa è in grado di adattarsi alle diverse condizioni operative che si susseguono durante il volo, lavorando sempre in prossimità dell’efficienza massima. A valle di uno studio sullo stato dell’arte di questa tecnologia, propedeutico alla scelta del profilo e al tipo di deformazione, è stato realizzato un modello 3D del profilo HQ2512 a cui è stato applicato un “morphing trailing edge”; si tratta di bordo d’uscita in grado di deformarsi, senza generare discontinuità superficiale, azionato elettricamente attraverso attuatori piezoelettrici MFC. Tale soluzione è stata anch’essa oggetto di verifiche sperimentali, svolte in galleria del vento, al fine di valutarne i benefici dal punto di vista aerodinamico e la validità del sistema di attuazione. Per entrambe le soluzioni, sono state effettuate misure sperimentali a bassi numeri di Reynolds (tipici delle applicazioni in cui si hanno basse velocità o superfici molto piccole), con lo scopo di simulare le condizioni operative standard degli aeromodelli in scala. Tra le finalità delle ricerche sopra descritte, vi è infatti quella applicare tali soluzioni a “sistemi arei a pilotaggio remoto” (comunemente detti droni) utilizzati per scopi scientifici.
The wing surfaces performances, used in aeronautical, sports or energy applications play an increasingly crucial role. Increasing aerodynamics efficiency in wind turbine blades or in classic aircraft, can have interesting economic and environmental implications. In this thesis two different solutions from an experimental point of view are evaluated, aimed to improve the aerodynamic efficiency of airfoils and wing surfaces. The first method is a passive boundary layer control systems, and consists of the application of "dimples" on a laminar airfoil NACA 642014A. The dimples are widely used in blunt body (suche as golf balls, cycling helmets etc.), to reduce the aerodynamic resistance but much less frequent on aerodynamic surfaces. Experimental measurements on two models of NACA 642014A (with and whitout dimples) were carried out in the environmental wind tunnel of the “Università Politecnica delle Marche”. The purpose is to evaluate the dimple's ability to reduce the laminar separetion bubble extension and reduce aerodynamic drag. The second solution consists in a deformable wing called "morphing wing". The main objective is to modify the surface geometry, acting variable camber; in this way the wing adapts to different operating conditions and always works close to maximum efficiency. A "morphing trailing edge system", electrically operated through piezoelectric actuators, was applied to HQ2512 airfoil; experimental measurements were also carried out at the Aeronautical Wind Tunnel of the “Università Politecnica delle Marche” for the sake of validation of the system. All the experimental measurements were performed at low Reynolds numbers (typical of a low speeds application or small bodies), with the aim of simulating the unmanned aerial veichles (UAV) conditions.

La precisione sulla misura della sezione d’urto del neutrino elettronico e muonico è limitata principalmente dalla conoscienza del flusso iniziale. La precisione attuale è dell’ordine del 5 − 10%. Il progetto ENUBET (Enhanced NeUtrino Beam from kaon Tagging) propone una nuova facility in grado di monitorare il fascio di neutrini prodotto da un fascio secondario di mesoni taggando il leptone corrispondente emesso nello stesso decadimento di pro- duzione. Questo tipo di studio pone diverse restrizioni sul fascio secondario, dal quale dipende soprattutto la distribuzione in energia dei neutrini che raggiungono il detector. In questo lavoro di tesi di dottorato si presentano gli studi effettuati per il design e l’ottimizzazione di una beamline a ener- gia modulare (Multi-Momentum Beamline) presso la sezione BE-EA-LE del CERN. Il layout proposto è ottimizzato per il trasporto di mesoni K+ e π+ con momento centrato in 8.5, 6 e 4 GeV/c. Attraverso questa tecnica è possi- bile monitorare l’energia di neutrini nell’area di interesse di esperimenti quali HyperK, T2K e DUNE tramite la stessa configurazione di magneti. Oltre alla modularità, la Multi-Momentum Beamline è caratterizzata da un angolo di produzione che permette un primo filtro dal fondo che raggiungerebbe il tunnel di decadimento. Inoltre, il design è composto da soli elementi già attualmente in uso al CERN. L’impiego di magneti pre-esistenti permette un’analisi quantitativa, oltre che qualitativa delle performance della beam- line oltre a un costo contenuto nell’implementazione.
The precision of the measurement of the cross-section of the electronic and muon neutrino is mainly limited by the knowledge of the initial flux. The cur- rent precision is on the order of 5−10%. The ENUBET (Enhanced NeUtrino Beam from kaon Tagging) project proposes a new facility capable of moni- toring the neutrino beam produced by a secondary meson beam by tagging the corresponding lepton emitted in the same production decay. This type of study places several restrictions on the secondary beam, that essentially de- fines the energy spectrum of the neutrinos reaching the far detector. In this Ph.D. thesis work, we present the studies carried out for the design and op- timization of a modular momentum beamline (Multi-Momentum Beamline) at the BE-EA-LE section of CERN. The proposed layout is optimized for the transport of K+ and π+ mesons with momentum centered around 8.5, 6 and 4 GeV/c. Using this beamline, it is possible to monitor the neutrino en- ergy in the area of interest of experiments such as HyperK, T2K, and DUNE through the same configuration of magnets. In addition to modularity, the developed multi-momentum beamline presents remarkable properties such as a very satisfactory neutrino yield, control of the background, and satisfactory beam properties and performance that are all discussed in detail. A special target optimization procedure for maximizing the hadron yield has also been devised. Furthermore, the design is made up of only elements already in use at CERN. The use of pre-existing magnets allows a quantitative as well as qualitative analysis of the performance of the beamline as well as a low cost in the implementation. Finally, a comparison between Monte-Carlo and data for the ENUBINO prototype, tested at CERN’s EAST area is presented.

This work is a comparative study of the variables of physical fitness and health (anthropometry and body composition, grip strength, front and back flexibility of the trunk, aerobic capacity VO2( max.) and cardiorespiratory valuation) among athletes and sedentary young females in the Autonomous Community of Extremadura. Its aim is to observe the benefits of physical activity and sport in the system and identify risk factors for health. For this, a total of 163 girls between 12 and 18 years of age (114 of them were athletes and the remaining 49 were sedentary girls) took part. They belong to the selection of Extremadura in several sports with aerobic, anaerobic and mixed-orientation. The results indicate significant differences in strength parameters, anthropometry and body composition, back flexibility, blood pressure (systolic and diastolic), and ventilatory capacity between both groups; RESUMO:O trabalho desenvolvido é um estudo comparativo das variáveis determinantes da aptidão física e saúde (antropometria e composição corporal, força de preensão manual, flexibilidade anterior e posterior do tronco, capacidade aeróbia( VO2 max.) e a avaliação cardiorrespiratória), entre jovens atletas e jovens sedentárias do sexo feminino na região da Extremadura. Pretende-se observar os benefícios que a actividade física e desportiva têm para o organismo e identificar alguns factores de risco para a saúde. Para esse efeito, participaram um total de 163 raparigas com idades entre os 12 e 18 anos, 114 eram atletas, pertencentes à selecção da Extremadura em vários desportos com uma orientação aeróbia, anaeróbia e mista, e um total de 49 raparigas sedentárias. Os resultados obtidos indicam diferenças significativas relativamente aos parâmetros de força, antropometria e composição corporal, flexibilidade posterior, pressão arterial (sistólica e diastólica), e capacidade ventilatória entre os dois grupos; RESUMEN:El trabajo a desarrollar trata de un estudio comparativo de las variables determinantes de la condición física y salud (antropometría y composición corporal, fuerza de prensión manual, flexibilidad anterior y posterior del tronco, capacidad aeróbica(VO2 max.) y valoración cardiorrespiratoria) entre jóvenes deportistas y sedentarios del sexo femenino en la Comunidad Autónoma de Extremadura. Se pretende observar los beneficios que la actividad físico-deportiva aporta al organismo e identificar algunos factores de riesgo para la salud. Para ello, participaron un total de 163 chicas con edades comprendidas entre los 12 y 18 años, 114 eran deportistas, pertenecientes a la seleccione extremeña de varios deportes con orientación aeróbica, anaeróbica y mixta, y un total de 49 chicas sedentarias. Los resultados obtenidos indican diferencias significativas relativas a parámetros de fuerza, antropometría y composición corporal, flexibilidad posterior, tensión arterial (sistólica y diastólica), y capacidad ventilatoria entre ambos grupos.

Lo studio che si ha in informatica ha come obiettivo la scoperta di algoritmi sempre più efficienti per riuscire, con componenti semplici, a svolgere compiti complessi, con il minore carico di lavoro possibile. Le applicazioni di tale studio trovano risultati anche nel campo del controllo adattativo di robot. Si vogliono confrontare tramite questo studio le osservazioni più importanti riguardati queste caratteristiche rese note dalla scienza e applicarle ai campi sopra citati per dimostrare l'effettivo valore e affidabilità che si guadagnano andando a utilizzare degli algoritmi che rispecchiano le stesse caratteristiche che si possono notare nel regno animale. La metodologia di interesse usata come caso di studio è quella del recupero di oggetti. Esistono numerose soluzioni a questo problema che possono trovare uso in molte realtà utili all'uomo. Ne verranno presentate e confrontate due all'interno di questo elaborato, studiando le caratteristiche positive e negative di entrambe. Questi due approcci sono chiamati a soglia fissa e a soglia variabile. Entrambe sono tipologie di adattamento che prendono spunto dal comportamento che hanno le colonie di formiche quando si muovono alla ricerca di cibo. Si è deciso di analizzare queste due metodologie partendo da una panoramica generale di come cooperano gli insetti per arrivare al risultato finale, per poi introdurre nello specifico le caratteristiche di entrambe analizzando per ognuna i risultati ottenuti tramite grafici, e confrontandoli tra di loro.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
Neste trabalho, a formulaÃÃo pseudo-clÃssica da superpartÃcula de Brinck-Schwarz relativÃstica e nÃo-relativÃstica à apresentada. Tal formulaÃÃo possui uma parte representada por variÃveis de Grassmann que descrevem os graus de liberdade de spin. Durante a formulaÃÃo da teoria, utilizou-se a teoria dos vÃnculos para possibilitar a quantizaÃÃo do sistema e foi construÃda tambÃm uma Lagrangeana que represente sistemas Grassmannianos. Tal sistema à invariante sob supersimetria e reparametrizaÃÃo. A equaÃÃo de Dirac surge como um vÃnculo da teoria.
In this work, the pseudo-classical formulation of relativistic and non-relativistic Brinck-Schwarz superparticle is presented. Such a formulation has a portion represented by Grassmann variables that describe the degrees of freedom of spin. During the formulation of the theory, we use the theory of constraints to allow quantization of the system and also we constructed a Lagrangian representing Grassmannian systems. Such a system is invariant under supersymmetry and reparameterizations. The Dirac equation appears as a constrainst of theory.

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CAPES
Estudos das propriedades óticas de aerossóis em escalas locais e suas relações com a radiação solar são de grande importância para a pesquisa atmosférica. Essas pesquisas contribuem para o entendimento das propriedades radiativas e seu processo de transmissão à superfície. Uma das formas de se avaliar os efeitos provocados pelos aerossóis é através da análise de suas propriedades óticas. Desta forma o presente trabalho desenvolve uma análise da Profundidade Ótica de Aerossóis (AOD) e do coeficiente de Angstrom (), assim como estima a Forçante Radiativa de Aerossóis (ARF) sobre a superfície em uma região de Cerrado no Estado de Mato Grosso. A região de estudo é acometida, todos os anos na estação seca, por inúmeros registros de focos de incêndios. Os dados adquiridos junto a AERONET (Aerosol Robotic Network) foram analisados e correlacionados com variáveis micrometeorológicas de precipitação, temperatura de superfície e umidade relativa. A AOD total para o comprimento de onda de 500nm e suas respectivas parcelas devido à fração fina e grossa de material particulado foi correlacionada, concluindose que a AOD nessa região possui uma alta correlação com a fração a moda fina de aerossóis, apresentando um coeficiente de correlação de Spearman de 0,975 com um intervalo de confiança na faixa de 0,996 a 0,981. Os valores obtidos para o coeficiente de Angstrom () indicaram grande relação do aumento da AOD com as partículas emitidas por queima de biomassa. Buscou-se investigar quantitativamente os valores de ARF em um período de transição de seca-úmida. Os valores de ARF foram obtidos através de medidas simultâneas de Profundidade Ótica de Aerossóis (AOD) para a faixa de 500nm e radiação solar na faixa do visível (Sw). Os picos para AOD 500nm chegaram a 1,6 no mês de setembro onde foram registrados 5.576 focos de incêndio no Estado de Mato Grosso. O valor da ARF para o dia 13-08-12 atingiu (-93,01 ± 8,46) Wm-2, sendo que a variação da AOD 500nm em 0,1 provocou uma queda de aproximadamente 80 Wm-2 sobre a superfície, durante o fim do mês de agosto e começo do mês de setembro os picos de ARF atingiram -120 Wm-2 para valores de profundidade ótica acima de 1,0.
Studies of the optical properties of aerosols on local scales and their relationship with solar radiation are of great importance for atmospheric research. These studies contribute to the understanding of the radiative properties and the process of transmission to the surface. One of the ways to assess the effects caused by aerosols is by analyzing their optical properties. Thus this paper provides an analysis of Aerosol Optical Depth (AOD) and the Angstrom coefficient () and estimates the Forcing Radiative of Aerosols (ARF) on the surface in a region of Cerrado in Mato Grosso. The study area is affected every year in the dry season by numerous records of outbreaks of fire. The data acquired from AERONET (Aerosol Robotic Network) were analyzed and correlated with micrometeorological variables precipitation, surface temperature and Relative Humidity. The total AOD to the wavelength of 500nm and their plots due to the fine and coarse fraction of particulate matter was correlated, concluding that the AOD in this region has a high correlation with the fine fraction of aerosols fashion, with a coefficient Spearman correlation of 0.975 with a confidence interval ranging from 0.996 to 0.981. The values obtained for the Angstrom coefficient () showed a large increase in the ratio of AOD to the particles emitted by biomass burning. We attempted to quantitatively investigate the values of ARF in a period of transition from dry-moist. The ARF values were obtained by simultaneous measurements of Aerosol Optical Depth (AOD) for the range of 500nm and solar radiation in the visible range (Sw). The peaks for AOD 500nm reached 1.6 in September where 5,576 fires in Mato Grosso were recorded. The value of ARF for the day reached 8.12.13 (-93.01 ± 8.46) Wm-2, with the variation of the AOD 500 nm in 0.1 caused a decrease of about 80 Wm-2 on the surface during the end of August and beginning of September peak ARF reached -120 Wm-2 for values above 1.0 optical depth.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
In this thesis we study the electronic properties of several systems of condensed matter physics using two different continuum models, the effective mass theory and the effective Dirac Hamiltonian. In several systems, there is an effective mass depending on position. Some models for the kinetic energy operator were proposed to describe these systems, but there is no definition of which one is the most appropriate. It is one of the oldest open questions in solid state physics. We propose a new model, where we consider all permutations among the operators and show that it satisfies the fundamental requirements of quantum mechanics. We use this model to obtain the minibands structure of a heterostructure composed by two different materials and compare our model with other models previously proposed. We also get the Schrödinger equation for a particle constrained to a curved surface with position dependent mass. We follow the da Costa approach, where there is a geometric potential. We show that the position dependent mass does not affect the geometric potential, contributing only to the kinetic part. We use this equation to study the electronic transport in a junction of two cylinders with different radii, with the effective mass varying with the cylinder radius. Using the effective Dirac Hamiltonian, we consider a graphene sheet on a periodic substrate heterostructure composed by two different materials. Each material induces a specific energy gap and Fermi velocity in the graphene, so the Dirac Hamiltonian has a gap (mass) term and a Fermi velocity depending on position. We write this operator taking into account that it has to be Hermitian and we obtain the minigaps induced by the substrate in the electronic structure of graphene. Motivated by experimental results, we study the effects of rotation on the electronic structure of carbon nanotubes, fullerene C60 and topological insulators, using an effective Dirac operator. In the carbon nanotube and C60 cases, the rotation adds a shift in the energy levels and a break in spin degeneracy. In the topological insulator case, the rotation adds only a shift in the energy.
Nesta tese estudamos as propriedades eletrônicas de diversos sistemas físicos da matéria condensada utilizando dois modelos contínuos distintos, o modelo de massa efetiva e o hamiltoniano de Dirac efetivo. Em vários sistemas existe o aparecimento de uma massa efetiva dependente da posição. Diversos modelos para o hamiltoniano cinético com massa efetiva variável foram propostos, mas não existe uma definição de qual seja o mais adequado. Essa é uma das questões mais antigas em aberto na física do estado sólido. Nós propomos um novo modelo, levando em conta todas as permutações possíveis entre os operadores e mostramos que ele satisfaz os requisitos fundamentais da mecânica quântica. Nós usamos esse modelo para obter a estrutura de minibandas de uma heteroestrutura formada por dois materiais diferentes e comparamos o nosso modelo com outros modelos propostos anteriormente. Também obtemos a equação de Schrödinger para uma partícula confinada a uma superfície curva com massa efetiva dependendo da posição. Seguimos a abordagem de da Costa, onde surge um potencial geométrico. Mostramos que a massa variável não altera a potencial geométrico, contribuindo apenas para a parte cinética. Nós usamos a equação obtida para estudar as propriedades de transporte eletrônico em uma junção de dois cilindros de raios diferentes, com a massa efetiva variando com o raio do cilindro. Utilizando um hamiltoniano de Dirac efetivo nós consideramos o grafeno sobre um substrato formado por uma heteroestrutura com dois materiais diferentes. Cada material induz um gap de energia e uma velocidade de Fermi específica no grafeno, fazendo com que tenhamos um hamiltoniano de Dirac com termo de gap (massa) e velocidade de Fermi dependendo da posição. Nós escrevemos esse operador levando em conta que ele tem que ser hermitiano e obtemos a estrutura de minibandas induzidas na estrutura eletrônica do grafeno pelo substrato. Motivados por resultados experimentais, nós também estudamos os efeitos da rotação na estrutura eletrônica do nanotubo de carbono, fulereno C60 e isolante topológico, utilizando um hamiltoniano de Dirac efetivo. Para o nanotubo de carbono e o C60 a rotação adiciona um deslocamento nos níveis de energia e há uma quebra na degenerescência de spin. No isolante topológico a rotação induz apenas um deslocamento na energia.

Al fine di descrivere appropriatamente le osservabili studiate tramite collisori adronici e/o leptonici, risulta cruciale una corretta comprensione delle correzioni non perturbative (che si manifestano come correzioni di potenza), lineari nel rapporto tra una scala di energia non perturbativa e la scala caratteristica del processo. Utilizzando un modello abeliano ricerchiamo tali effetti nella distribuzione in momento trasverso di un bosone Z prodotto con un jet in collisioni adroniche, essendo questa una delle osservabili meglio misurate presso LHC. La presenza delle correzioni non perturbative di cui sopra impedirebbe di raggiungere la precisione sperimentale, anche considerando ordini superiori nello sviluppo perturbativo. Non avendo individuato alcuna correzione di questo tipo tramite tecniche semi numeriche, abbiamo scelto di adottare un approccio più rigoroso dal punto di vista teorico, fornendo una spiegazione attorno al manifestarsi di tali correzioni di potenza. Tale comprensione teorica è stata applicata allo studio delle variabili di shape in annichilazione $e^+e^-$, con particolare attenzione allo studio del C-parametro e del thrust, e ottenendo per tali osservabili una stima delle correzioni non perturbative nella regione dei tre jet per la prima volta. In tale lavoro è stata altresì ottenuta un'espressione fattorizzata per le correzioni non perturbative per alcune osservabili, con un termine dipendente dalla variazione dell'osservabile a seguito dell'emissione di un partone soffice, e un termine costante e universale, proporzionale al cosiddetto Milan factor. Tali osservabili sono ampiamente utilizzate al fine di estrarre valori della costante di interazione forte $\alpha_s$ e costituiscono il contesto ideale al fine di compiere studi di QCD perturbativa. È dunque estremamente importante ottenere stime affidabili delle correzioni non perturbative nell'intera regione di spazio delle fasi rilevante per i fit di $\alpha_s$.
Understanding leading non-perturbative corrections, showing up as linear power corrections, is crucial to properly describe observables both at lepton and hadron colliders. Using an abelian model, we examine these effects for the transverse momentum distribution of a $Z$ boson produced in association with a jet in hadronic collisions, that is one of the cleanest LHC observables, where the presence of leading non-perturbative corrections would spoil the chance to reach the current experimental accuracy, even considering higher orders in the perturbative expansion. As we did not find any such corrections exploiting semi-numerical techniques, we looked for a rigorous field-theoretical derivation of them, and explain under which circumstances linear power corrections can arise. We apply our theoretical understanding to the study of event-shape observables in $e^+e^-$ annihilation, focusing in particular on $C$-parameter and thrust, and obtaining for them an estimate of non-perturbative corrections in the three-jet region for the first time. We also derived a factorisation formula for non-perturbative corrections, with a term describing the change of the shape variable when a soft parton is emitted, and a constant universal factor, proportional to the so-called Milan factor. These observables are routinely used to extract the strong coupling constant $\alpha_s$ and they constitute an environment to test perturbative QCD. It is then extremely important to obtain reliable estimates of non-perturbative corrections in the whole kinematic region relevant for the $\alpha_s$ fits.

The necessity of a proper modelization of molecular diffusion in solution phase chemistry in order to rationalize properties and observables of the same give rise to the question \which tools from the theoretical chemistry field can be used?". The most commonly used approaches in order to answer this question relies on the usage of stochastic models. Then, depending on the particular conformational dynamics of the studied systems and the time scale on which molecular relaxation phenomena occurs, different models and tools can fit the desired level of description. Among all these approaches I focused on the Smoluchowski equation since its wide application in the theoretical chemistry community and since it well adapts to many diffusion problems in solution phase chemistry. Smoluchowski equation is a partial derivative equation that describes how the probability density of a set of coordinates evolves along time. Once the equation is solved, the probability profiles enclose informations upon specific properties and observables. My research activity in this field focused on new and more general numerical approaches to the solution of Smoluchowski equation with the application to specific case studies of chemical interest. Initially I have studied a class of methods apt to solve partial derivative differential equations. In particular, the chosen methodology is known as Discrete Variable Representation (DVR). Successively I have used this methodology in order to solve the one-dimensional Smoluchowski equation, in the stochastic processes framework applied to molecular systems. Comparing this method with preexisting ones I have validated this novel approach. This method has been implemented on a FORTRAN code with the aim of having an integrated approach for the solution of the one-dimensional Smoluchowski equation. Then I focused my research activity on the enhancement of the several physico- chemical ingredients that enter into the one-dimensional Smoluchowski equation. In par- ticular I extended an earlier diffusion tensor model including the dependence of the same on a generalized coordinate. Then, applying DVR theory to one-dimensional Smoluchowski equation I gave a more complete and general theoretical scenario of the same. In the framework of stochastic processes applied to molecular systems I have implemented and validated this novel approach. At last, for what concerns the Smoluchowski equation solved with DVR, I extended the same formalism to coupled one-dimensional Smoluchowski equations along the same generalized coordinate where there is the possibility of reactive exchanges of population and/or sinking terms between different coupled states. This is of great interest for example in the context of photoexcitations, where one has a population evolving through a ground and an excited state, along a specific coordinate, e.g. a twisting coordinate. From the temporal evolution of the probability density of the excited state one can retrieve lifetimes and/or compute the time resolved spectra at different times, etc. This last implementation merge the use of DVR basis with product approximation and diffusion tensor calculation along a generalized coordinate. The result is an integrated computational \black-box" tool in the framework of Gaussian software that give access to the generic user the possibility to study these specific systems of interest.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
In thiswork,weinvestigateaclassofspace-timesbycalculatingtheloopvariables for differentcurves,intheparticularcasewherethepathstakenareclosed(circles),we obtain theso-calledholonomytransformations,fromwhichthetraceprovidesthematrix obtained intheWilsonloopgravitational.Firstwediscussthecasewherethegravita- tional fieldisgeneratedbyacylindricalshell,withoutrotation,intheapproximationof weak field.Thenwestudythespace-timesofGödelandFriedman-Robertson-Walker.We also investigatethespace-timesgeneratedbyacosmicstringwithinternalstructure.Fi- nally wediscusstheKottlerspace-timeandsomemodelsofwormholes.Tocalculatethe loop variablesweusetheperturbationexpansiontechnique,whichwecall perturbative method, andtechniquethroughtheLorentztransformationoflocalcoordinates,which we callthe exact method. Theobtainedresultsshowusthewaythesecontourvariables contain informationsrelatedtothegeometricalandtopologicalpropertiesofeachoneof these space-times.
Neste trabalho,investigamosumaclassedeespaços-tempoatravésdocálculodasva- riáveis decontornoparadiferentescurvas,quenocasoparticular,emqueoscaminhosto- mados sãofechados(círculos),obtêm-seasdenominadastransformaçõesdeholonomias, do qualotraçodamatrizobtidanosforneceoloopdeWilsongravitacional.Primeiro abordamos ocasoemqueocampogravitacionalégeradoporumacascacilíndrica,sem rotação,naaproximaçãodecampofraco.Emseguida,estudamososespaços-tempode Gödel eodeFriedman-Robertson-Walker.Tambéminvestigamosocenáriogeradopor uma cordacósmicacomestruturainterna.Porfim,abordamosoespaço-tempodeKöttle e algunsmodelosdewormholes.Paraocálculodasvariáveisdecontornoutilizamosa técnica daexpansãoperturbativa,oqualdenominamosde método perturbativo, eatéc- nica viatransformaçãodecoordenadasdeLorentzlocal,oqualdenominamosde método exato. Osresultadosnosmostramdequemaneiraessasvariáveisdecontornodetectam as característicasgeométricasetopológicasdecadaumdessesespaços-tempo.

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Rejected by Renata de Souza Nascimento (renata.souza@fgv.br), reason: Pedro, Será necessário alguns ajustes na formatação das primeiras páginas, conforme as normas da ABNT. Segue abaixo: CAPA: Retirar a acentuação do nome GETULIO. CAPA e CONTRA CAPA: São Paulo deve estar em letras maiúsculas. Centralizar o título Agradecimentos e retirar os espaços entre os parágrafos. Centralizar os títulos RESUMO e ABSTRACT e retirar os dois pontos. O texto deve estar abaixo do título. Após alterações, realize uma nova submissão. Att. on 2015-09-14T21:18:30Z (GMT)
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Este trabalho propõe um método para corrigir a distorção observada na distribuição de população dos municípios brasileiros presente nos dados de Censo Demográfico. Essa distorção se caracteriza por uma concentração elevada de municípios com valores de população próximos das mudanças de faixa do Fundo de Participação de Municípios (FPM). O método identifica os municípios candidatos a ajuste, ou seja, com maiores distorções obtidas através de um método Jackknife, e sugere uma correção para sua população de acordo com um modelo linear que segue a Lei de Zipf de distribuição de população de cidades (ZIPF, 1949). Após o ajuste o proposto, o teste de McCrary (2008) captura significativa redução nas descontinuidades na distribuição da população dos municípios para os anos de 2000, 2007 e 2010.
This paper proposes a correction method for the distortion observed in the Brazilian municipalities population distribution in the Demographic Census data. This distortion is defined by a heightened concentration of municipalities with population close to the values of the interchanging levels of the Municipal Participation Fund (Fundo de Participação de Municípios ­ FPM). This method identifies the candidate municipalities for adjustment by evaluating their distortion, obtained through a Jackknife method application, and suggests a corrected value for its population, according to a linear model which follows Zipf`s Law for cities (ZIPF, 1949). After the proposed adjustment, the McCrary test (2008) observes significative reduction of discontinuities in the municipalities population distribution for the years 2000, 2007 and 2010.

I due nuclei tematici principali del presente elaborato sono il modello del Quantum Random Walk (QRW) e il fenomeno della localizzazione di Anderson, i quali vengono prima trattati separatamente nei loro aspetti più rilevanti e in seguito ne viene esaminata la relazione reciproca. In particolare, dopo una breve introduzione sul Random Walk classico, si espone la formalizzazione teorica del QRW e si procede ad un'analisi dettagliata della distribuzione di probabilità del processo, con maggiore attenzione rivolta al QRW di Hadamard. La localizzazione di Anderson viene illustrata a partire dal modello tight-binding di un elettrone in un reticolo, di cui si affronta sia la versione in assenza di disordine che quella 1D disordinata, con inizialmente una descrizione di natura teorica e dopo uno studio di tipo numerico basato su diversi metodi computazionali. L'ultima parte è dedicata alla connessione tra i due argomenti e rappresenta il punto di arrivo dell'intero elaborato, dal momento che essa verte sulla localizzazione di Anderson per un QRW 1D con disordine. Viene presentato il modello e si ricavano risultati analitici che caratterizzano le proprietà di localizzazione del sistema, con approfondimento dei casi di disordine completo e di disordine debole. Anche nel capitolo finale è riservato spazio alle simulazioni, che vengono impiegate per studiare numericamente la localizzazione e per verificare la correttezza degli esiti dei calcoli teorici.

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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
In this work we investigate the stochastic behavior of a large class of systems with variable damping which are described by a time-dependent Lagrangian. Our stochastic approach is based on the Langevin treatment describing the motion of a classical Brownian particle of mass m. Two situations of physical interest are considered. In the first one, we discuss in detail an application of the standard Langevin treatment (white noise) for the variable damping system. In the second one, a more general viewpoint is adopted by assuming a given expression to the so-called collored noise. For both cases, the basic diffententiaql equations are analytically solved and al the quantities physically relevant are explicitly determined. The results depend on an arbitrary q parameter measuring how the behavior of the system departs from the standard brownian particle with constant viscosity. Several types of sthocastic behavior (superdiffusive and subdiffusive) are obteinded when the free pamameter varies continuosly. However, all the results of the conventional Langevin approach with constant damping are recovered in the limit q = 1
Neste trabalho n?s investigamos o comportamento estoc?stico de uma grande classe de sistemas com amortecimento vari?vel descritos por uma lagraniana dependente do tempo. Nossa abordagem estoc?stica ? baseada no formalismo de Langevin descrevendo o comportamento de uma part?cula browniana cl?ssica de massa m. Duas situa??es de interesse f?sico s?o consideradas. Inicialmente, uma aplica??o do tratamento padr?o de Langevin (ru?do branco) para viscosidade vari?vel ? discutido em detalhe. Na segunda abordagem, um ponto de vista mais geral ? adotado supondo uma dada express?o para o chamado ru?do branco. Em ambos os casos as equa??es diferenciais b?sicas s?o analiticamente resolvidas, e todas as quantidades fisicamente relevantes s?o explicitamente determinadas. Os resultados dependem de um par?metro arbitr?rio (q) medindo como o comportamento din?mico do sistema se afasta daquele apresentado pela part?cula browniana com viscosidade constante. V?rios tipos de comportamentos estoc?sticos (subsifusivos and superdifusivos) s?o obtidos quando o par?metro livre q varia continuamente. Contudo, no limite q -> 1, todos os resultados da abordagem de Langevin convencional s?o recuperados

Using Bean and Metzner's conceptual framework related to non-traditional student attrition, the responsible use of Federal Pell Grants was studied by examining the retention and academic performance of college-credit seeking students in a public college in Florida that predominantly offered two year degree programs. Also analyzed were differences between Pell Grant recipients and non-recipients among various demographic categories. Chi-square tests of independence indicated that statistical significance existed between Pell Grant recipients and non-recipients in retention rates from fall to spring terms, as well as in the demographic variables of academic performance, gender, ethnicity, age group, residency, and credit hours achieved. Only the variable of ethnicity showed a medium practical effect size, with all the other variables indicating a small to no practical effect size.
Ed.D.
Doctorate
Educational and Human Sciences
Education and Human Performance
Educational Leadership; Higher Education Track

Każda gospodarka otwarta podlega nieustannym zaburzeniom pochodzącym zarówno z jej wnętrza, jak również z otoczenia zagranicznego. Szoki te mogą dotyczyć zarówno strony podażowej, np. niedobór surowców, jak też popytowej, związanej m.in. z preferencjami konsumentów. Ważnym szokiem popytowym są zmiany podatków. Wpływają one na poziom dochodu do dyspozycji, kształtując przez to decyzje firm i gospodarstw domowych w zakresie konsumpcji i oszczędności. Jest to szczególnie widoczne na giełdach, gdzie inwestorzy na bieżąco oceniają każdą nową informację pod kątem jej potencjalnego wpływu na gospodarkę i wyniki finansowe firm. W okresie pogorszenia koniunktury, zmniejszają oni swoje zaangażowanie w aktywa ryzykowne, przesuwając kapitał w stronę aktywów bezpiecznych. Dochodzi wtedy do wzrostu premii za ryzyko zawartej w cenach aktywów. W teorii ekonomicznej premia za ryzyko definiowana jest jako różnica pomiędzy oczekiwaną stopą zwrotu z aktywów ryzykownych a stopą procentową wolną od ryzyka. Określa się ją także jako iloczyn poziomu ryzyka, mierzonego np. odchyleniem standardowym stopy zwrotu oraz parametru reprezentującego tzw. „awersję” do ryzyka, którą można też nazwać „ceną” ryzyka. Nastawienie podmiotów gospodarczych względem ryzyka wynika z kształtu funkcji użyteczności z osiąganego dochodu, która dla większości podmiotów gospodarczych jest funkcją wklęsłą. Tym samym, skłonność do nabywania ryzykownych aktywów powinna być średnio wyższa w okresach dobrej koniunktury, gdy krańcowa użyteczność z każdej kolejnej jednostki dochodu jest niewielka. Wzrasta wtedy popyt na aktywa finansowe o podwyższonym ryzyku, jak np. akcje, a premia za ryzyko maleje. W przeciwnym przypadku, gdy dochody są niskie, ewentualna utrata nawet niewielkiej ich części staje się bardzo „dotkliwa”, przez co preferowane są aktywa uważane za bezpieczne. Mimo że teoria wyraźnie łączy zmiany premii za ryzyko ze zmianami dochodu do dyspozycji, siła tej zależności rzadko jest tematem badań empirycznych. Przyczyną takiego stanu rzeczy jest wysoka złożoność problemu. Po pierwsze, premia za ryzyko jest parametrem nieobserwowalnym. Po drugie, poszczególne rodzaje podatków mogą teoretycznie mieć odmienny wpływ na premię, a same wpływy podatkowe kształtowane są przez bardzo dużą liczbę czynników, które trudno połączyć w jednym modelu. Po trzecie, zmiany podatków są z reguły dyskutowane i zapowiadane na długo przed ich faktycznym wprowadzeniem, przez co ich ewentualny wpływ na premię za ryzyko może być widoczny na długo przed wejściem w życie proponowanych przepisów. Ostatni problem nazywany jest przewidywalnością polityki fiskalnej (fiscal foresight). Stanowi on duże utrudnienie przy szacowaniu empirycznych zależności pomiędzy zmianą podatków a innymi zmiennymi w gospodarce, sprawiając że siła impulsu podatkowego, mierzona tradycyjnymi metodami może okazać się niedoszacowana. Głównym celem niniejszej pracy jest odpowiedź na pytania o kierunek i siłę zależności pomiędzy zmianami podatków a premią za ryzyko. Tym samym, praca uzupełnienia dostępną literaturę o empiryczne badanie związku pomiędzy zmianami podatków a premią za ryzyko. W ramach analizy wyznaczono szereg czasowy premii za ryzyko, wykorzystując przy tym zarówno popularne w literaturze zmienne fundamentalne jak np. stopa dywidendy, jak też wskaźniki analizy technicznej takie jak średnie ruchome. Wyznaczony szereg premii został następnie włączony do modelu VAR, zawierającego też szeregi czasowe wpływów podatkowych i wydatków budżetu centralnego, PKB, inflację CPI oraz stopę procentową w postaci oprocentowania miesięcznych depozytów na rynku międzybankowym. Model VAR został następnie zidentyfikowany za pomocą różnych metod ekonometrycznych, w tym restrykcji krótko i długookresowych, restrykcji na znak oraz zmiennej narracyjnej. Szczególnie ważne są wyniki otrzymane za pomocą dwóch ostatnich metod, które umożliwiają przezwyciężenie problemu przewidywalności polityki fiskalnej. Otrzymane wyniki potwierdziły duże znaczenie tego, czy wybrana metoda identyfikacji odpowiada na problem przewidywalności polityki fiskalnej. Funkcje reakcji otrzymane za pomocą restrykcji krótko i długookresowych wskazały na znikomą reakcję premii za ryzyko, w granicach 0,1 pkt. proc i były wyraźnie słabsze od tych otrzymanych za pomocą bardziej zaawansowanych metod, tj. identyfikacji za pomocą restrykcji na znak oraz za pomocą zmiennej narracyjnej, w przypadku których wzrost premii wyniósł około 1,5 pkt proc. Wyniki z oszacowanych modeli wskazały także na silny związek premii za ryzyko z koniunkturą gospodarczą, rozumianą jako dynamika PKB. Premia rośnie wraz z obniżeniem dynamiki PKB oraz obniża się wraz z poprawą dynamiki wzrostu gospodarczego. Większość otrzymanych rezultatów jest zgodna z teorią ekonomiczną i finansową, w myśl której obawa o spadek dochodu zmniejsza zainteresowanie inwestorów aktywami o wyższym ryzyku. W efekcie podmioty gospodarcze są skłonne zapłacić za te aktywa cenę niższą od tej, którą można by wyznaczyć jako matematyczną wartość oczekiwaną spodziewanych cen we wszystkich możliwych przyszłych stanach gospodarki. Taka sytuacja prowadzi do wzrostu premii za ryzyko. Otrzymane w tej pracy wyniki wskazują też, że podwyżka podatków jest szczególnie niekorzystna dla inwestycji, których silny spadek może wynikać z obniżenia oczekiwanej stopy zwrotu po opodatkowaniu. Dodatkową destymulantą inwestycji może też być sam wzrost premii za ryzyko, który zwiększa koszt kapitału dla firm. Podwyżka podatków działa zatem na inwestycje zarówno w sposób bezpośredni jak i pośredni, poprzez trudniejszy dostęp do finansowania. Otrzymane wyniki wskazują natomiast, że po podwyżce podatków dynamika PKB dość szybko zaczyna wracać w stronę scenariusza bazowego. Poprawa ta może wynikać z kilku czynników. Po pierwsze, wzrost podatków ma zazwyczaj na celu sfinansowanie nowych, być może potrzebnych, wydatków publicznych lub obniżenie deficytu budżetowego. Po drugie, w następstwie wzrostu podatków obniża się niepewność dotycząca stanu finansów publicznych w przyszłości, co sprzyja działalności przedsiębiorstw. Oprócz tego, w krótkim okresie dynamika PKB może być wspierana spowolnieniem importochłonnych inwestycji, co poprawia saldo handlu zagranicznego. Porównanie reakcji dynamiki PKB i dynamiki inwestycji na wzrost podatków przemawia też za hipotezą poprawy produktywności inwestycji realizowanych w warunkach wyższych stawek podatkowych. Potwierdzenie hipotez o spowolnieniu importu bądź zmianie „jakości” inwestycji wymagałoby jednak dodatkowych badań, wykraczających poza temat tej pracy. Niezależnie od przyczyn, wysoka odporność gospodarki na wzrost stawek podatkowych jest ważnym wnioskiem płynącym z tej pracy, szczególnie ciekawym z punktu widzenia polityki gospodarczej.
Every open economy is subject to disturbances, coming from both its interior and foreign environment. These shocks may concern the supply side, e.g. a shortage of raw materials, as well as the demand side, related, among others, to consumer preferences. Tax changes are an important demand shock. They affect the level of disposable income, shaping agents’ decisions on consumption and savings. This is especially visible on stock exchanges, where investors constantly evaluate each new information in terms of its potential impact on the economy and financial results of companies. During the downturn, they reduce their holdings of risky assets, shifting capital towards safe assets. Then the risk premium included in the asset prices increases. In economic theory, the risk premium is defined as the difference between the expected rate of return on risky assets and the risk-free interest rate. It is also defined as the product of the risk level, measured e.g. with a standard deviation of the rate of return and a parameter representing agents’ attitude towards risk. The latter is called "risk aversion" or the "price” of risk. Agents’ attitude towards risk results from the shape of the income utility function which for most financial entities is a concave function. Thus, the propensity to purchase risky assets should be on average higher in “good times”, when marginal utility from each subsequent income unit is low. The demand for risky financial assets, such as stocks, increases, and the risk premium falls. Otherwise, if the income is low, the possible loss of even a small part of income is severe, which means that assets considered safe are preferred. While the theory of economics and finance clearly links the risk premium with disposable income, the strength of this relationship is rarely the subject of empirical research. The reason for this is the high complexity of the problem. First, the risk premium is an unobservable parameter. Secondly, different types of taxes can theoretically have a different impact on premium, and the tax revenues themselves are shaped by a very large number of factors that are difficult to be combined in one model. Thirdly, tax changes are usually discussed and announced well before their actual implementation, so that their impact on the risk premium can be seen well before the proposed regulations become law. The last problem is called fiscal foresight and makes it difficult to estimate empirical relationship between the change in taxes and other variables in the economy. Because of the fiscal foresight the significance of the tax impulse may be underestimated if measured by traditional methods. The key aim of this thesis is to answer the questions about the direction and strength of the relationship between tax changes and the risk premium. As part of the analysis, a time series of risk premium for WIG index was estimated, using both popular in the literature fundamental variables such as dividend rate as well as technical indicators as moving averages. The time series of risk premium was then included in the VAR model, also containing time series of central budget tax revenues and expenditure, GDP, CPI inflation and interest rate on monthly interbank deposits. Then, the VAR model was identified using various econometric techniques, including short- and long-term restrictions, sign restrictions, and a narrative method. Particularly important are the results obtained using the last two methods as they are capable to overcome the problem of fiscal foresight. The obtained results confirmed the importance of whether the chosen identification method takes into account the problem of fiscal foresight. Impulse responses estimated with short- and long-term restrictions indicated a negligible reaction of the risk premium to tax increase, within 0.1 percentage point, and were clearly weaker than those obtained by advanced methods, i.e. identification by sign restrictions and narrative method, for which the increase in the premium was close to 1.5 percentage point. The results also indicate a strong relationship between the risk premium and the economic sentiment, measured by GDP dynamics. The premium increases with the decline in GDP dynamics and decreases with the improvement in the dynamics of economic growth. Most of the results obtained are consistent with economic and financial theory, according to which the fear of a decrease in income reduces investors' interest in risky assets. As a result, agents are willing to pay for these assets a price much lower than that which could be calculated as the mathematical expected value of their price in all possible future states of the economy. This situation leads to an increase in the risk premium. The results obtained in this thesis also indicate that the tax increase is particularly unfavourable for investments, the strong decrease of which may result from the decrease in the after tax profitability of investment projects. The increase in risk premium itself is also harmful for investments as it increases the cost of capital to companies. The tax rate therefore influence investments both directly, and indirectly through lower availability of financing. On the other hand, the estimated models indicate that after a rise in taxes, GDP dynamics starts to return to the baseline scenario quite quickly. This improvement can be due to several factors. First, tax increases are usually aimed at financing new, perhaps needed, public spending. Secondly, as a result of the increase in taxes, the uncertainty about the state of public finances in the future is decreasing, which favours business operations. In addition, in the short term, GDP growth may be supported by a slowdown in import-intensive investments, which improves the foreign trade balance. Comparing the responses of GDP and investment dynamics to tax increase also supports the hypothesis of improving the productivity of investments carried out in the environment of higher tax. This hypothesis could additionally explain the quick economic recovery. However, confirmation of the hypotheses about a slowdown in imports or a change in the quality of investments would require an extension of the conducted research. Regardless of its causes, the high resistance of economic growth to an increase in tax rates is an important conclusion, particularly interesting from the point of view of economic policy.

Projecto / Códigos JEL: M12, M52.
Este trabalho analisa o enquadramento fiscal português de cada remuneração sobre o trabalho, com o objectivo de definir um conjunto de acções de melhoria, ao nível da eficiência fiscal, na definição das políticas de remuneração. Neste sentido, começámos por analisar a diversa legislação e jurisprudência relativamente quer às remunerações sobre o trabalho, quer aos impostos que incidem sobre essas remunerações, o que permitiu definir com exactidão o âmbito de aplicação de cada remuneração. Posteriormente, e num âmbito mais prático, procedemos à quantificação da carga fiscal sobre cada remuneração, quer do lado da empresa, quer do lado do trabalhador. Com foco na optimização fiscal, definimos ainda o potencial de optimização fiscal associado à aplicação de cada remuneração acessória, face ao salário base, de forma a chegarmos a conclusões acerca das remunerações mais vantajosas em termos fiscais. Ao nível da política fiscal, concluímos que existem ganhos, quer ao nível de receita fiscal, quer ao nível da confiança dos contribuintes, se tornarmos a política fiscal mais eficiente, simples e igualitária, sugerindo que se proceda a um alargamento da base tributável (eliminando isenções sujeitas a critérios confusos) paralelamente à redução das taxas de tributação. Por outro lado, concluímos que, com o objectivo de uma maior eficiência fiscal, seria imprescindível que empresas e trabalhadores negociassem em conjunto o modelo de remuneração, tendo como foco a maximização do bem-estar comum. Neste sentido, a optimização fiscal será atingida através da escolha de remunerações acessórias em detrimento de uma parte do salário base.
This paper intends to analyze the Portuguese fiscal frame to each kind of remuneration over work, with the goal of defining a set of improvement actions in terms of fiscal efficiency for remuneration policies definition. Following this, we started by analyzing the different legislation and jurisprudence referring whether to the kinds of remuneration over work, whether to taxes on those kinds of remuneration, which allowed to define precisely the scope of application of each one of them. Then, at a more practical level, we quantified the tax burden of each kind of remuneration, to both sides of company and worker. Focusing on fiscal optimization, we also defined the fiscal optimization potential associated to each variable remuneration application, towards base salary, so that we could come to a conclusion about the most attractive kind of remuneration in fiscal terms. In terms of fiscal policy, we conclude that there are gains, both in terms of tax revenue, or the level of taxpayers’ commitment, if we make fiscal policy become more efficient, simple and egalitarian, suggesting that there should be a broadening of the tax base (eliminating exemptions subject to confused criteria) parallel to the reduction of tax rates. Moreover, we conclude that, with the goal of greater fiscal efficiency, it is essential that companies and workers would negotiate together the compensation model, focusing on maximizing the common welfare, which will be achieved mainly through the choice of variable remuneration rather than a part of the base salary.