On common agency with informed principals

This thesis consists of three chapters that have as unifying subject the frame-work of common agency with informed principals. The first two chapters analyze the economic effects of privately informed lobbying applied to tariff protection (Chapter 1) and to customs unions agreements (Chapter 2). The third chapter investigates the choice of retailing strutures when principals (the producers) are privately informed about their production costs. Chapter 1 analyzes how lobbying affects economic policy when the interest groups have private information. I assume that the competitiveness of producers are lobbies private information in a Grossman and Helpman (1994) lobby game. This allows us to analyze the e¤ects of information transmission within their model. I show that the information transmission generates two informational asymmetry problems in the political game. One refers to the cost of signaling the lobby's competitiveness to the policy maker and the other to the cost of screening the rival lobby's competitiveness from the policy maker. As an important consequence information transmission may improve welfare through the reduction of harmful lobbying activity. Chapter 2 uses the framework of chapter 1 to study a customs union agreement when governments are subject to the pressure of special interest groups that have better information about the competitiveness of the industries they represent. I focus on the agreement's effect on the structure of political influence. When join a customs union, the structure of political pressure changes and with privately informed lobbies, a new effect emerges: the governments can use the information they learn from the lobby of one country to extract rents from the lobbies of the other country. I call this the "information transmission effect". This effect enhances the governments'bargaining power in a customs union and makes lobbies demand less protection. Thus, I find that information transmission increases the welfare of the agreement and decreases tari¤s towards non-members. I also investigate the incentives for the creation of a customs union and find that information transmission makes such agreement more likely to be politically sustainable. Chapter 3 investigates the choice of retailing structure when the manufacturers are privately informed about their production costs. Two retailing structures are analyzed, one where each manufacturer chooses her own retailer (exclusive dealing) and another where the manufacturers choose the same retailer (common agency). It is shown that common agency mitigates downstream competition but gives the retailer bargaining power to extract informational rents from the manufacturers, while in exclusive dealing there is no downstream coordination but also there are no incentives problem in the contract between manufacture and retailer. A pre- liminary characterization of the choice of the retailing structure for the case of substitute goods shows that when the uncertainty about the cost increases relatively to the size of the market, exclusive dealing tends to be the chosen retailing structure. On the other hand, when the market is big relatively to the costs, common agency emerges as the retailing structure. This thesis has greatly benefited from the contribution of Professors Humberto Moreira and Thierry Verdier. It also benefited from the stimulating environment of the Toulouse School of Economics, where part of this work was developed during the year of 2007.

New evidence on trade liberalization and productivity growth

Although the subject of a large number of studies, the debate on the links between trade reform and productivity growth is still unresolved and most studies at the micro level have not been able to establish a relationship between the two phenomena. Brazil provides a natural experiment to study this issue that is seldom available: it was one of the closest economies in the world until 1988, when trade reform was launched, and intra-industry data are available on an annual basis before, during and after liberalization. Using a panel of industry sectors this paper tests and measures the impact of trade reform on productivity growth. Results confirm the association between the former and the latter and show that the magnitude of the impact of tariff reduction on the growth rates of TFP and output per worker was substantial. Our data reveal large and widespread productivity improvement, so that the estimations in this paper are an indication that liberalization had an important effect on industrial performance in the country. Cross-sectional differences in protection are also investigated.

The impacts of TTIP on Brazil

The objective of this project is to analyze the effects for Brazil of the conclusion of TTIP. This is approached under different hypotheses: considering the effects on Brazil of a TTIP with the reduction of only tariff barriers between US and EU; introducing a partial reduction of non-tariff barriers; and, at last, with a complete reduction of these barriers. To finalize, an audacious alternative is assumed: a hypothetical participation of Brazil in the TTIP under a partial reduction of agricultural tariffs by the US and EU markets, and under a full liberalization of their agricultural markets. The methodology used to estimate non-tariff barriers was presented in the Ecorys Project (2009) developed by Berden e Francois to the European Commission.

Exchange rate misalignments and international trade policy: impacts on tariffs

The debate on “exchange wars and trade wars” is raising the attention of experts on international trade and economics. The main purpose of this paper is to analyze the impacts of exchange rate misalignments on one of the most traditional trade policy instruments – tariffs, as defined by the WTO – World Trade Organization. It is divided into three sections: the first one examines the effects of exchange rate variations on tariffs and its consequences for the multilateral trade system; the second explains the methodology used to determine exchange rate misalignments and also presents its results for Brazil, US and China; and the third summarizes the methodology applied to calculate the impacts of exchange rate misalignments on the level of tariff protection through an exercise of “misalignment tariffication”

The distortion of currencies misalignments on trade Instruments: or why currencies wars are not over

The negotiations of mega agreements between the US and the Pacific countries (TPP) and between the US and the EU (TTIP) are raising the attention of experts on international trade law and economics. TPP and TTIP are proclaimed to be the designers of the rules for the XXI Century. Old trade instruments such as tariffs are said to be no more important for TTIP because tariffs are negligible among those partners but significant to for TPP. Another relevant agreement in negotiation is between the EU and Mercosul, where tariffs are the most important issue in discussion. The main purpose of this paper is to shows that tariff are important for all these agreements, not because of its nominal value, but because the impacts of exchange rate misalignments on tariffs are so significant that all concessions can be distorted by overvalued and by devaluated currencies. The article is divided into several sections: the first gives an introduction to the issue; the second explains the methodologies used to determine exchange rate misalignments and also presents some results for Brazil, US and China; the third summarizes the methodology applied to calculate the impacts of exchange rate misalignments on the level of tariff protection through an exercise of “misalignment tariffication” and examines the effects of exchange rate variations on tariffs and their consequences for the multilateral trading system; the fourth creates a methodology to estimate exchange rates against a basket of currencies (a virtual currency of the World) and a proposal to deal with persistent and significant misalignments related to trade rules. The fifth presents some estimates for the main PTAs. The conclusions are present in the last section

EU-Mercosur trade relations: impacts of exchange rate misalignments on tariffs

The issue of “trade and exchange rate misalignments” is being discussed at the G20, IMF and WTO, following an initiative by Brazil. The main purpose of this paper is to apply the methodology developed by the authors to exam the impacts of misalignment on tariffs in order to analyse the impacts of misalignments on the trade relations between two customs unions – the EU and Mercosur, as well as to explain how tariff barriers are affected. It is divided into several sections: the first summarises the debate on exchange rates at the WTO; the second explains the methodology used to determine exchange rate misalignments; the third and fourth summarises the methodology applied to calculate the impacts of exchange rate misalignments on the level of tariff protection through an exercise of ‘misalignment tariffication’; the fifth reviews the effects of exchange rate misalignments on tariffs and its consequences for the trade negotiations between the two areas; and the last concludes and suggests a way to move the debate forward in the context of regional arrangements

Nuclear-follower foraging associations among Characiformes fishes and Potamotrygonidae rays in clean waters environments of Teles Pires and Xingu rivers basins, Midwest Brazil

Por meio de observações sub e supra-aquáticas foram registradas associações alimentares do tipo nuclear-seguidor entre três espécies de peixes characiformes - Chalceus epakros, Hemiodus semitaeniatus e Hemiodus unimaculatus - e uma espécie de raia de água doce - Potamotrygon orbignyi - nas bacias dos rios Teles Pires e Xingu, no Centro-Oeste do Brasil. Os peixes teleósteos foram observados seguindo as raias quando estas revolviam o substrato à procura de invertebrados, formando discretas nuvens de sedimento. Essas situações atraíram os peixes que se aproximaram das raias para se alimentar de pequenas presas e outros tipos de alimentos expostos desta forma. Esse é um típico exemplo de relação comensal onde um participante é beneficiado enquanto o outro não é prejudicado e representa o segundo registro na literatura de associação alimentar do tipo nuclear-seguidor entre raias potamotrigonídeas e peixes teleósteos, demonstrando o potencial de estudos naturalísticos para a descoberta de novas interações envolvendo espécies de peixes de água doce.

Recent Studies on Neoechinorhynchus curemai Noronha, 1973 (Acanthocephala: Neoechinorhynchidae), in Prochilodus lineatus Valenciennes, 1836, from Volta Grande Reservoir, MG, Brazil

O presente trabalho estudou a helmintofauna do curimbatá, Prochilodus lineatus Valenciennes, 1836, do reservatório de Volta Grande, MG, Brasil. Foram analisados 18 peixes com comprimento médio de 46,7 ± 1,1 cm e peso médio de 1.674,8 ± 75,6 g, sendo que 15 apresentaram acantocéfalos no intestino com prevalência de 83,3%. O helminto foi identificado como Neoechinorhynchus curemai Noronha, 1973 (Acanthocephala: Neoechinorhynchidae), que diferiu das outras espécies descritas pelas dimensões dos caracteres e pela morfologia. da descrição original de N. curemai difere pelas maiores dimensões dos testículos, pela glândula de cimento alongada, pela presença de núcleos nos lemniscos, pelas dimensões dos ovos e pelos maiores ganchos da probóscide presentes na segunda e na terceira fileiras nos machos e na primeira fileira nas fêmeas. Foi observada menor porcentagem ocupada pelo sistema reprodutivo em relação ao tronco da fêmea. A observação dos parátipos de N. curemai de Noronha (1973) mostrou grande semelhança com os do presente trabalho. Este fato complementa a descrição do helminto em outra localidade.

Body lipid deposition in Nile tilapia fed on rations containing tannin

O objetivo deste trabalho foi avaliar o efeito de fontes e níveis de tanino em rações para tilápia-do-nilo (Oreochromis niloticus), durante a engorda, sobre o desempenho produtivo e deposição lipídica corporal. Foram utilizados 342 peixes, distribuídos em 18 tanques. As rações foram preparadas com milho, variedades de sorgo com baixo e alto teor de tanino, e com ácido tânico a 0,08, 0,34, e 0,60%. Ganho de peso, conversão alimentar aparente e taxa de eficiência protéica não foram influenciados pelos tratamentos. A maior deposição lipídica corporal foi observada nas dietas com ácido tânico (14,39%); a dieta de sorgo com alto teor de tanino resultou em carcaças mais magras (12,01%) do que as de sorgo com baixo teor de tanino (13,31%). Dietas com sorgo proporcionaram menores teores de gordura visceral. A presença de tanino nas rações não prejudicou o desempenho produtivo da tilápia-do-nilo.

Effects of different sampling intervals on apparent protein and energy digestibility of common feed ingredients by juvenile oscar fish (Astronotus ocellatus)

O presente estudo avaliou a digestibilidade aparente da proteína e da energia de ingredientes (farelo de soja, farinha de peixe, farelo de trigo e milho) por juvenis de apaiari (Astronotus ocellatus) usando dois diferentes intervalos de coleta (30 min. e 12h). Os 160 juvenis de apaiari utilizados (22,37 ± 3,06 g de peso corporal) foram divididos em quatro tanques rede plásticos e cilíndricos, cada um colocado em um tanque de alimentação de 1.000 L. O experimento foi inteiramente casualizado em esquema fatorial 2 x 4 (2 intervalos de coleta de fezes e 4 ingredientes foram) com quatro repetições. Os testes estatísticos não detectaram efeito da interação entre o intervalo de coleta e tipo de ingrediente nos coeficientes de digestibilidade. O intervalo de coleta não afetou a digestibilidade da proteína e da energia. As características físicas das fezes dos juvenis de apaiari aparentemente as tornam menos sensíveis à perda de nutrientes por lixiviação, permitindo intervalos de coleta maiores. A digestibilidade da proteína dos ingredientes avaliados foi semelhante, mostrando que a digestibilidade aparente de ingredientes animais e vegetais por juvenis de apaiari é eficiente. Os coeficientes de digestibilidade da energia foram maiores para a farinha de peixe e o farelo de soja comparado a farelo de trigo e milho. Ingredientes ricos em carboidratos (farelo de trigo e milho) apresentaram os piores coeficientes de digestibilidade da energia e, portanto, não são usados eficientemente pelos juvenis de apaiari.

Line-pack management for producing electric power on peak periods

The distribution of natural gas is carried out by means of long ducts and intermediate compression stations to compensate the pressure drops due to friction. The natural gas compressors are usually driven by an electric motor or a gas turbine system, offering possibilities for energy management, one of these consisting in generating energy for use in-plant or to commercialize as independent power producer. It can be done by matching the natural gas demand, at the minimum pressure allowed in the reception point, and the storage capacity of the feed duct with the maximum compressor capacity, for storing the natural gas at the maximum permitted pressure. This allows the gas turbine to drive an electric generator during the time in which the decreasing pressure in duct is above the minimum acceptable by the sink unit. In this paper, a line-pack management analysis is done for an existing compression station considering its actual demand curve for determining the economic feasibility of maintaining the gas turbine system driver generating electricity in a peak and off-peak tariff structure. The potential of cost reduction from the point of view of energy resources (natural gas and electric costs) is also analyzed. (C) 2010 Elsevier Ltd. All rights reserved.

Freshwater stingrays: study of epidemiologic, clinic and therapeutic aspects based on 84 envenomings in humans and some enzymatic activities of the venom

Freshwater stingrays are very common in the Parana, Paraguay, Araguaia, and Tocantins Rivers and tributaries in Brazil. This study presents the clinical aspects of 84 patients injured by freshwater stingrays. Intense pain was the most conspicuous symptom. Skin necrosis was observed in a high percentage of the victims, mostly fishermen and bathers. The initial therapeutic procedures, like immersion of the affected member in hot water were effective in the initial phases of the envenoming, especially in the control of the acute pain; however, they did not prevent skin necrosis. By SDS-PAGE, the freshwater stingray (Potamotrygon falkneri) venom extract presented a major band of approximately 12 kDa. Several other components distributed between 15 and 130 kDa were detected in the venom extract. Many components with molecular mass above 80 and 100 kDa have gelatinolytic and caseinolytic activities, respectively. Hyaluronidase activity was detected only in a component around 84 kDa in P. falkneri venom extract. Our results demonstrated that the presence of these enzymes could explain partially the local clinical pictures presented by patients wounded by freshwater stingray. (C) 2004 Elsevier Ltd. All rights reserved.

The spiny dogfish ('cacao-bagre'): description of an envenoming in a fisherman, with taxonomic and toxinologic comments on the Squalus gender

The authors report an injury caused by a spiny dogfish (Squalus sp) in a professional fisherman that was got hurt in the left hand for a spine in the dorsal fin of the fish and felt excruciating local pain for 6 h and manifested local edema and erythema. The sharks of the Squalus gender, in a similar way to the gender Heterodontus, present two spines in position previous to the dorsal fins, with channels presenting a whitish mass, composed of great and vacuolated cells that produce venom. The Squalus gender has a complex taxonomy, with five nominal species mentioned in Brazil: S. acanthias, S., blainvillei, S. cubensis, S. megalops and S. mitsukurii. The species associated to the injury belongs to the group 'megalops/cubensis'. A detailed study on the taxonomy and toxinology of the Squalus gender in Brazil would be of vital importance in the resolution of those problems and it would serve as subsidy for any other works involving their representatives, besides with aspects of envenoming that this gender can cause and that has rare citations in the literature. (c) 2005 Elsevier Ltd. All rights reserved.

Coalescence of teeth in fishes

In this paper the concept of coalescence of teeth previously defined for the Tetraodontoid fishes is extended to some other teleostomes. Comments are made on the «dentigerous plates» of non-teleostomian fishes and on the dermal plates bearing odontodes found in some fossil groups.

Two 5S rDNA arrays in Neotropical fish species: is it a general rule for fishes ?

In this paper we describe Southern blot hybridization results probed with 5S rRNA genes for several Neotropical fish species representing different taxonomic groups. All the studied species showed a general trend with the 5S rDNA tandem repeats organized in two distinct size-classes. At the same time, data on 5S rDNA organization in fish genome were summarized. Previous information on the organization and evolution of 5S rRNA gene arrays in the genome of this vertebrate group are in agreement with the Southern results here presented. Sequences obtained for several fish species have revealed the occurrence of two distinct 5S rDNA classes characterized by distinct non-transcribed spacer sequences, which are clustered in different chromosomes in some species. Moreover, the 5S rDNA loci are generally distributed in an interstitial position in the chromosomes and they are usually not syntenic to the 45S rDNA. The presence of two classes of 5S rDNA in several non-related fish species suggests that this could be a common condition for the 5S rRNA gene organization in the fish genome.