Commodity Taxation and Social Insurance

We investigate optimal commodity taxation in a social insurance framework based on Varian (1980). We show that the tax prescriptions in this moral hazard framework are notably similar to those derivetaxation are valid in this setup. We incorporate pre-committed goods - those whose consumption must be decided before the resolution of uncertainty - and show that tax prescriptions are also analogous to the existing literature. The robustness of tax rules across these setups is explained by the relaxation of incentive compatibility constraints.

Optimal exchange rate policy, optimal incomplete taxation and business cycles

Implementation and collapse of exchange rate pegging schemes are recur- rent events. A currency crisis (pegging) is usually followed by an economic downturn (boom). This essay explains why a benevolent government should pursue Þscal and monetary policies that lead to those recurrent currency crises and subsequent periods of pegging. It is shown that the optimal policy induces a competitive equilibrium that displays a boom in periods of below average de- valuation and a recession in periods of above average devaluation. A currency crisis (pegging) can be understood as an optimal policy answer to a recession (boom).

On the optimality of the Friedman Rule with heterogeneous agents and non-linear income taxation

We study the optimal “inflation tax” in an environment with heterogeneous agents and non-linear income taxes. We first derive the general conditions needed for the optimality of the Friedman rule in this setup. These general conditions are distinct in nature and more easily interpretable than those obtained in the literature with a representative agent and linear taxation. We then study two standard monetary specifications and derive their implications for the optimality of the Friedman rule. For the shopping-time model the Friedman rule is optimal with essentially no restrictions on preferences or transaction technologies. For the cash-credit model the Friedman rule is optimal if preferences are separable between the consumption goods and leisure, or if leisure shifts consumption towards the credit good. We also study a generalized model which nests both models as special cases.

Essays on household taxation and competition between heterogeneous firms

Essa tese é constituída por três artigos: "Tax Filing Choices for the Household", "Optimal Tax for the Household: Collective and Unitary Approaches" e "Vertical Differentiation and Heterogeneous Firms".

Main problems with the taxation of civil society organizations in Brazil: certifications and impact on payroll

The objective of this paper is to identify and analyze the main problems in the taxation—regarding both taxes themselves and compliance costs of taxation—of civil society organizations in Brazil. This study is qualitative descriptive research. A multiple case study with 26 organizations was performed. The results show that the problems mainly affect organizations with lower revenue and that do not work in the areas of education, health or social care. The main problems involve the taxation of the payroll and the difficulties related to obtaining and maintaining certifications. The study concludes with suggestions for the improvement of the regulatory framework.

Taxation of couples: a mirrleesian approach to collective households

Esta dissertação apresenta uma abordagem alternativa para o problema de taxação de famílias. Mais especificamente modelamos a decisão familiar com um modelo de barganha de Nash em que os o governo determina de forma ótima as utilidades de discórdia. Demonstramos um Princípio da Revelação para esse modelo de forma a reduzir a classe de mecanismos possíveis, além disso calculamos os ganhos do mecanismo ótimo em relação a outros mecanismos razoáveis por meio de exemplos. Discutimos algumas implicações associadas ao mecanismo ótimo.

Optimal Mirrleesian taxation in non-competitive labor markets

We study optimal labor income taxation in non-competitive labor markets. Firms offer screening contracts to workers who have private information about their productivity. A planner endowed with a Paretian social welfare function tries to induce allocations that maximize its objective. We provide necessary and sufficient conditions for implementation of constrained efficient allocations using tax schedules. All allocations that are implementable by a tax schedule display negative marginal tax rates for almost all workers. Not all allocations that are implementable in a competitive setting are implementable in this noncompetitive environment.

COMPOSITION OF FRESHLY HARVESTED BRAZILIAN ROYAL JELLY - IDENTIFICATION OF CARBOHYDRATES FROM THE SUGAR FRACTION

Samples of Brazilian royal jelly from Africanized Apis mellifera were analysed in order to determine the gross composition: crude moisture ranged from 67.80% to 69.40%, crude protein from 15.80% to 16.70%, crude lipid from 2.90% to 3.98% and-total sugars from 11.40% to 11.50%. The sugar fraction was investigated and revealed the presence of the following compounds identified by their retention time during HPLC analysis: ribose, fructose, glucose, sucrose, mannose, trehalose, erythritol, adonitol and mannitol.

Nutritional and chemical composition of culinary-medicinal Royal Sun Agaricus (the Himematsutake mushroom) Agaricus brasiliensis S. Wasser et al. (agaricomycetideae)

The objective of the study was to determine the nutritional and chemical composition (carbohydrates, proteins, lipids, calcium, and iron), water and ash content, and the caloric value of powdered fruiting bodies from six strains and from a mixture of strains of the culinary-medicinal mushroom Agaricus brasiliensis. The Kruskal-Wallis nonparametric and multiple comparisons tests and the Pearson correlation coefficient were used, with a 5% significance level. First, the results showed that strain 99/30 had a similar nutritional composition to the mixed sample. Second, when comparing strain nutrients to the mixture nutrients, the highest levels of carbohydrates, proteins, and calcium were in strain 99/25, and the highest levels of lipids were in strains 97/11, 99/28, and 99/30. Strain 99/30 was highest both in caloric value and moisture content. Finally, the mixture was established as a good source of macronutrients and micronutrients, and strain 99/30 was the closest to the mixture in nutritional composition.

Jelleines: a family of antimicrobial peptides from the Royal Jelly of honeybees (Apis mellifera)

Four antimicrobial peptides were purified from Royal Jelly of honeybees, by using reverse phase-HPLC and sequenced by using Q-Tof-MS/MS: PFKLSLHL-NH2 (Jelleine-I), TPFKLSLHL-NH2 (Jelleine-II), EPFKLSLHL-NH2 (Jelleine-III), and TPFKLSLH-NH2 (Jelleine-IV). The peptides were synthesized on-solid phase, purified and submitted to different biological assays: antimicrobial activity, mast cell degranulating activity and hemolysis. The Jelleines-I-III presented exclusively antimicrobial activities against yeast, Gram+ and Gram- bacteria; meanwhile, Jelleine-IV was not active in none of the assays performed. These peptides do not present any similarity with the other antimicrobial peptides from the honeybees; they are produced constitutively by the workers and secreted into Royal Jelly. (C) 2004 Elsevier B.V. All rights reserved.

Morphohistochemical characterization of the perivisceral fat body in royal and worker female castes in different ages of Atta sexdens rubropilosa ants (Hymenoptera, Formicidae)

The morphohistochemical study of the fat body in royal and worker castes of Atta sexdens rubropilosa revealed that this tissue is made up of trophocytes and oenocytes, trophocytes being the cells with cytoplasmic inclusions and irregular nuclei and the oenocytes cells with homogeneous cytoplasm and rounded nuclei. The trophocytes of queens presented many lipidic and proteic granules, while those of workers presented trophocytes with fine granulation in the cytoplasm constituted mainly by lipids and carbohydrates. The oenocytes from the worker caste of A. s. rubropilosa presented cytoplasm filled mainly with lipoproteic material.

Taxation and the architecture of the international economic system

Includes bibliography