Taxes are major source of public funds to finance government expenditures. Tax authorities impose different kind of taxes and employ many agents to collect taxes effectively. Some dutiful taxpayers will undoubtedly pay their tax liabilities while many others will not. The Internal Revenue Service in the United States reports that the estimate of income tax liability not collected is about 17, which translates into 345 billion for 2001. It is important to make a distinction between tax evasion and tax avoidance. The distinguishing characteristic of evasion is illegality. Whether the reason for not paying tax liability is avoidance or evasion, economic models of taxation need to be changed in the light of these realities. In this study, I analyze some of the economic problems of tax evasion/avoidance. In the first chapter, I discuss the relationship between number of tax audits, tax administration reform and tax compliance in Turkey. In recent years, many developing countries have carried out reforms in their tax administration to increase their efficiency in collecting taxes. In 2005, the tax authority in Turkey established Tax Office Directorates (T.O.D.s) in 29 provinces for the purpose of controlling the underground economy, improving taxpayer assistance, and increasing auditing efficiency. By using the panel data on province level tax returns, my analysis answers two questions. First, I examine the effect of audits on reported income and reported tax liability. By controlling for the detectibility of evasion and other socioeconomic variables, I find that audits have the same effectiveness in increasing reported income and reported tax liability. Second, I investigate the effect of establishing T.O.D.s in 29 provinces on compliance in those provinces. I find that T.O.D.s are effective at the extensive margin rather than the intensive margin. Thus, establishing T.O.D.s had no significant effect on the compliance level of existing taxpayers while it increased the number of tax returns significantly. In the second chapter, I analyze the excess burden on income tax when tax avoidance matters. I present a simple static labor supply model with endogenous asset choice. Then, I examine how tax avoidance through asset trading a ects the labor supply response and the excess burden of income tax. Furthermore, I discuss the implications of the tax policy analysis and show that a failure to account for avoidance responses may lead to errors when estimating how tax reform affects labor supply, tax revenue, and the welfare cost of taxation. Because of tax avoidance through tax arbitrage, the progressivity of a given tax system will be less than what the formal tax system implies. In the third chapter,we study the Marginal Cost of Funds in the existence of tax evasion. We develop a general equilibrium model of tax evasion, including the expected utility of taxpayers and three different revenue-raising government policies. In this rich model environment, we analytically derive the marginal cost of funds (MCF) for the alternative policy instruments. We consider two main fiscal reforms: the revision in the nonlinear tax scheme and the changes in enforcement mechanism (the audit and penalty rates). First, we derive the MCF for the tax reform and find its key determinants. The derived MCF is greater than the previous ones since it includes a "risk-bearing cost" as well as tax distortion. The reform in enforcement mechanism generates MCFs in different forms. Two more MCFs with respect to audit and penalty rates are presented. Finally, we compare these three different MCFs in numerical example and provide some policy implications. / text

Submitted by Thiago Pereira (tpereira@fgvmail.br) on 2011-11-15T22:29:07Z No. of bitstreams: 1 Thesis_Final.pdf: 1369841 bytes, checksum: fd36f0ac693d22db03a6309d1b005d09 (MD5) / Approved for entry into archive by Andrea Virginio Machado (andrea.machado@fgv.br) on 2011-11-17T13:05:32Z (GMT) No. of bitstreams: 1 Thesis_Final.pdf: 1369841 bytes, checksum: fd36f0ac693d22db03a6309d1b005d09 (MD5) / Made available in DSpace on 2011-12-06T10:07:51Z (GMT). No. of bitstreams: 1 Thesis_Final.pdf: 1369841 bytes, checksum: fd36f0ac693d22db03a6309d1b005d09 (MD5) Previous issue date: 2011-03-25 / This thesis is dedicated to study of tax schedule. I investigate how a tax schedule could affect the individuals’ choice and consequently the resources of the country. I show how a tax schedule induce the individuals’ choice, defining hence the allocations of labor, output and consumption of society. In the first and the second chapters I examine the taxation of individuals, while in the third and the fourth chapter I analyze the incidence of levies on different agents of economy. In the chapter one, I examine the optimal tax schedule, following Mirrlees (1971) e Saez (2001). I show how would be the optimal tax schedule in Brazil, charactering by a deeper income inequality among the individuals. Moreover, I investigate a affine tax schedule, that is considered an alternative tax schedule between the current and optimal tax schedule. In the second chapter I analyze the tax schedule known as equal sacrifice. I show how the tax schedule derived by Young (1987), that was renewed by Berliant and Gouveia (1993), behavior itself in the efficiency test derived byWerning (2007). In the third and the fourth chapter I examine how tax reform proposals would affect the Brazilian’s economy. In the third chapter I investigate how a tax reform affects different social classes. In chapter four, I study the better directions to a tax reform in Brazil, showing which rearrange of levies is the less inefficient to the country. In the end, I investigate the effects of two tax reform proposals in the Brazilian economy. I define the gains of output and welfare in each proposal. I call the special attention to gains/loses of short run, because they could make no possible to approve a tax reform, even though the reform could good effects in the long run. / Esta tese dedica-se ao estudo dos sistemas tributários. Eu investigo como um sistema tributário afeta as escolhas dos indivíduos e consequentemente os recursos do país. Eu mostro como um sistema tributário induz as escolhas das pessoas, determinado assim as alocações de trabalho, produto e consumo da economia. No primeiro e segundo capítulo eu examino a taxação sobre os indivíduos, enquanto que no terceiro e quarto capítulos analiso a incidîncia tributária sobre os diferentes agentes da sociedade. No capítulo um, eu examino o sistema tributário ótimo, seguindo Mirrlees (1971) e Saez (2001). Eu mostro como seria este sistema tributário no Brasil, país com profunda desigualdade de renda entre os indivíduos. Ademais, eu investigo o sistema tributário afim, considerado uma alternativa entre os sistemas atual e o ótimo. No segundo capítulo eu analiso o sistema tributário conhecido como sacríficio igual. Mostro como o sistema tribuária derivado por Young (1987), redesenhado por Berliant and Gouveia (1993), se comporta no teste de eficiência derivado por Werning (2007). No terceiro e quarto capítulo eu examino como propostas de reforma tribuária afetariam a economia brasileira. No capítulo três investigo como uma reforma tributária atingiria as diferentes classes socias. No capítulo quatro, eu estudo as melhores direções para uma reforma tributária no Brasil, mostrando qual arranjo de impostos é menos ineficiente para o país. Por fim, investigo os efeitos de duas propostas de reforma tributária sobre a economia brasileira. Explicito quais os ganhos de produto e bem estar de cada proposta. Dedico especial atenção aos ganhos/perdas de curto prazo, pois estes podem inviabilizar uma reforma tributária, mesmo esta gerando ganhos de longo prazo.

The first essay studies the Marginal Cost of Funds in the existence of tax evasion. We develop a general equilibrium model of tax evasion, including the expected utility of taxpayers and three different revenue-raising government policies. In this rich model environment, we analytically derive the marginal cost of funds (MCF) for the alternative policy instruments. We consider two main fiscal reforms: the revision in the nonlinear tax scheme and the changes in enforcement mechanism (the audit and penalty rates). First, we derive the MCF for the tax reform and find its key determinants. The derived MCF is greater than the previous ones since it includes a "risk-bearing cost" as well as tax distortion. The reform in enforcement mechanism generates MCFs in different forms. Two more MCFs with respect to audit and penalty rates are presented. Finally, we compare these three different MCFs in numerical example and provide some policy implications. The second essay explores optimal tax structure in the presence of status effect. When the consumption of certain goods affects one's social status, this externality creates two opposite effects in a society. Seeking higher status through “positional goods" gives individuals much incentive to supply labor but still allocates income for less “nonpositional goods" as well. In this case, differential taxes on positional goods work as corrective instruments to internalize the social cost stemming from status seeking. Furthermore, the differential taxes generate revenue that can be used to alleviate preexisting income tax distortion. Thus, the differential taxes on positional goods could give so called “double dividend." I develop a game-theoretic model in which each individual with a different labor productivity unknown to the others engages in a status-seeking game, and the government has a revenue requirement. Then I show that, under a condition in which utility is separable between positional goods and leisure, a revenue-neutral shift in the tax mix away from nonlinear income taxes towards positional-good taxes enhances welfare. Hence, the differential taxes on positional goods are necessary together with the nonlinear income taxes for an optimal tax structure. The third essay explores the impact of increasing capital mobility on regional growth and environment. I develop an endogenous growth model in which each local government competes against the others, to induce imperfectly mobile stock of capital into its region. Then I show that an increase in capital mobility generates “tax importing" due to which each locality experiences a higher growth rate and more degraded environment. That is, the increasing mobility dampens the capital tax and transfers the burden of pollution abatement to the locality. This finding supports the hypothesis of “race to the bottom" in environmental standards. Identifying a reduction in overall welfare of residents, I consider two alternative federal interventions in the model: uniform environmental standard and requirement of lump sum transfer or tax. Both of these federal instruments enhance the residents' welfare. / text