This research uses the optimal control theory to construct two kinds of dynamic economic systems, which are an economic system without externalities and with externalities. Within each economic system both the centralized economy model and the decentralized economy model are included. The centralized economy (a social planner) model representes a kind of ideal economy, and the goal what the social planner pursues is that the resource allocation of the society satisfies the Pareto Efficiency criteria. On the other hand, the decentralized economy model (consists of a representative producer and a representative consumer) demonstrates the real economy, where economic agents persue their own best interests. While constructing the models, goods market equilibrium, labors market equilibrium, the dynamic accumulation process of capital, and the dynamic accumulation course of pollution are under consideration. Then, I apply optimal control method to get the first order conditions, and compare these f.o.c¡¦.s to verify whether they are unanimous. This paper proves that when externalities of pollution does not exist in the dynamic economic system, the decentralized economy model can achieve the Pareto Efficiency. On the contrary, when externalities of pollution emerges in the dynamic economic system, the decentralized economy model cannot reach Pareto Efficiency. If the externalities of pollution is internalized by the dynamic decentralized economic system economy, it will coincide with Pareto Efficiency. Besides, Pigouvian tax is still an effective policy instrument. Finally, I discuss all dynamic models in this paper to find out whether there exists a long-term and stable steady state. I find stable steady state, saddle-point equilibria, do exist under certain restrictions.

This paper uses the optimal control theory to construct dynamic economic model. The primary purpose of this paper is to discuss how different policies alter the choice problem of the firm and influence the allocation of funds to existing and new research and development activities. I analyze how the fixed-cost regulatory standard and the marginal-cost standard let firm consider externality, in order to protect the consumer of asymmetric information and avoid the problem of adverse selection. The firm maximizes expected profit. At the same time I want to know how the consumer acceptance, mark and audit affect the farmer to purchase the quantity of seed and the allocation of funds . We want to discuss how different price influence the option input path, the option quantity path and the option path . I discuss the different between ultimatum and static model. Finally, I discuss dynamic models in this paper to find out whether there exists a long-term and stable steady state. Saddle-point stability exists under certain restrictions.

This thesis was focused on the influence of the tax practice of the courts on the assessment of a tax and the retrospective assessment in the Czech Republic. The purpose was to find out if the present law about the tax and fees administration is a sufficient procedural tax norm and if the existing practice of the courts provides us by its interpretation and integral attitude with reasonable juristic certainty of the tax subjects as well as the tax administrator when in the assessment of a tax and retrospective assessment process. Furthermore the new procedural norm which is just being approved these days in law area was examined: if it brings more suitable legal regulations in the selected areas and if it takes into account the conclusions of the practice of the courts. Finally the conclusions which confirmed expectations in the beginning of this thesis were made. The tax administration law can't act as the basic tax norm because its actual reading contains too many deficiencies. Thereunto from the downright analysis arises that the practice of the courts, which is disunited in its resolutions, for ensuring the integral and right procedure of tax assessment and retrospective assessment can't act. The present situation could be improved by coming into enter be of the new procedural tax law -- The Tax Regulation.

The recent entry of new reinsurers, besides the traditional/state/monopolist, changed the domestic insurance market, changing in profound ways how insurance companies work with reinsurance transactions. The relationship between the reinsurance level and solvency ratios, taxes and determinants was a subject analyzed by international and national studies, the latter researched the market during the pre-opening period (until 2007). In this context, this study ana- lyzes, through a pooled linear regression model, if the use of reinsurance by the Brazilian insurance companies, between 2011 and 2013, was influenced by the solvency and taxes, profitability and size of these companies. According to the international studies, there was no statistical significance for solvency variables. The “size” showed that smaller insurers are risk- averse and thus need higher levels of reinsurance. The proxy taxes had a positive significance, suggesting that national insurers use reinsurance as a tax management tool. The profitability variable was effective to explain the use of reinsurance by national insurance companies. The most profitable insurance companies tend to invest more in managing their risks by making greater use of reinsurance for its less profitable operations. This study found evidence that reinsurance is used by Brazilian insurance companies, not only as a risk management tool, but also for managing taxes and results. / La reciente entrada de nuevos reaseguradores, además del tradicional/estatal/monopolista, han creado una nueva faceta en el mercado nacional de seguros, cambiando drásticamente las características de los reaseguros contratados por las compañías de seguros. La relación del reaseguro con los índices de solvencia, tributos y los factores determinantes de este fue el blanco de muchas investigaciones internacionales y nacionales, estas últimas se realizaron en el período previo a la apertura del mercado (hasta el 2007). En este contexto, el presente estudio analiza, a través de un modelo de regresión lineal con datos pooled, si el uso del reaseguro por parte de las aseguradoras brasileñas durante el período 2011- 2013 fue influenciado por los niveles de solvencia, los tributos, la rentabilidad y el tamaño. Según las investigaciones internacionales, no hay un resultado estadísticamente significativo para las variables de solvencia. El determinante “tamaño” indicó que las aseguradoras más pequeñas tienen mayor rechazo al riesgo y por lo tanto el nivel de reaseguro es más alto. El proxy de tributos presentó significancia positiva, lo que sugiere que las aseguradoras nacionales utilizan el reaseguro como herramienta de gestión tributaria. El proxy de rentabilidad fue eficaz, lo que explica su relación con el nivel de reaseguro utilizado por las compañías de seguros nacionales; esto indica que las compañías de seguros nacionales más rentables tienden a invertir más en la gestión de sus riesgos al usar más el reaseguro en sus operaciones menos rentables. El presente estudio encontró indicios de que el reaseguro es utilizado por las compañías de seguros de Brasil,no solo como una herramienta de gestión de riesgos, sino también en la gestión tributaria y de resultados. / A recente entrada de novos resseguradores, além do tradicional/estatal/monopolista, deu nova cara ao mercado de seguros nacional, modificando de modo profundo as características das operações de resseguros contratadas pelas seguradoras. A relação do nível de resseguro com índices de solvência, de tributos e com determinantes deste, foi alvo de pesquisas internacionais e nacionais, sendo as últimas apenas no período pré-abertura do mercado (até 2007). Neste contexto, este estudo analisa, por meio de modelo de regressão linear com dados pooled, se o uso do resseguro pelas seguradoras brasileiras, no período de 2011 a 2013, foi influenciado pelos níveis de olvência, tributos, rentabilidade e tamanho. Em consonância com as pesquisas internacionais, não foi encontrada significância estatística para as variáveis de solvência. O determinante «Tamanho» indicou que seguradoras menores possuem maior aversão ao risco e, assim, níveis mais elevados de resseguro. A proxy de tributos apresentou significância positiva, sugerindo que as seguradoras nacionais utilizam o resseguro como ferramenta de gestão tributária. A proxy de rentabilidade mostrou-se eficaz para explicar o relacionamento com o nível de resseguro utilizado pelas seguradoras nacionais, indicando que as seguradoras nacionais mais rentáveis tendem a investir mais no gerenciamento de seus riscos fazendo maior uso do resseguro em suas operações que as menos rentáveis. O presente estudo encontrou indícios de que o resseguro é utilizado pelas seguradoras brasileiras, não só como uma ferramenta de gestão de riscos, mas também na gestão tributária e de resultados.

This thesis was focused on the influence of the development of a law opinion in the section of terms for assesment of a tax on a tax collection in the Czech republic. The purpose was to find out if the law about the tax and fees administration was a sufficient procedural tax norm in the section of terms for assessment of a tax, if existed the practice of the Supreme Administrative Court, which would edit, explain and improve interpretation provision § 47 Terms for assesment of tax which was wrote in the law about tax and fees administration. Furthermore was analyzed if the new procedural norm, the tax regulation, effective from 1. 1. 2011, was settled with interpretation the practice of the courts and what changes become against adjustment betray into the law about tax and fees administration. At the close work were make results, that the law about tax and fees administration was imperfect procedural norm in the section of terms for assesment of a tax and that the new procedural law, the tax regulation, which is more detailed specifies in the section of terms for assessment of a tax, can contribute to a better orientation in those problems.

This thesis focuses in its content on the impact of changes in the rate of value added tax on the subjects of the pharmaceutical market. Thesis explains the basic concepts of taxation and simultaneously describes the theoretical basement of price and reimbursement regulation of medicines and foods for special medical purposes. The thesis contains an analysis of the actual impact of changes in the rate of value added tax on the expenses of health insurance companies and patients.