Buy-or-sell auctions

This paper develops a game theoretic model of a "Buy-or-Sell" auction. Participants have to submit both a bid and an offer price for up to one of the many units of the good being auctioned. The bid-ask spread is set in advance by the auctioneer. Such an auction was used by the Central Bank of Brazil to intervene in the foreign exchange market during the exchange rate crawling-peg regime (1995-1999). I investigate whether such mechanism is more effective than standard intervention auctions to prevent speculative attacks in the context of managed exchange rate regimes.

A model of rural conflict : violence and land reform policy in Brazil

In the past ten years the struggle for land in Brazil has taken the shape of invasions of private land by welI organized groups of land less squatters. It is argued in this paper that these invasions and the resulting contlicts are a direct response to the land reform program which has been adopted by the govemment since 1985. which is based on the expropriation of farms and the creation of settlement projects. The set of formal and informal institutions which compromise the land reform program are used as the background for a game-theory model of rural contlicts. T estable implications are derived trom this model with particular emphasis on the etfect of policy variables on violence. These are then tested with panel data at state levei from 1988 to 1995. - It is shown that govemment policy which has the intent of reducing the amount of violence has the opposite etfect of leading to more incentives for contlicts.

Electoral control in the presence of gridlocks

This article presents a game-theoretic partisan model of voting and political bargaining. In a two-period setup, voters ¯rst elect an executive incumbent and the legislators from a pool of candidates belonging to di®erent parties. Once elected, the executive and the legislature bargain over a budget. Party origin and a relevant parameter of the economy, the state of the world, in°uence the bargaining cost, such that political gridlocks may occur. At the end of the ¯rst period voters observe the outcome of bargaining but do not observe the true estate of the world, and decide whether or not to reelect the same parties for the Executive and the Legislature. The model con¯rms the very recent literature by showing that voters tend to have more °exible reelection criteria when they believe the true state of the world is likely to be unfavorable. On the other hand, when voters believe the true state of the world is likely to be favorable, they become more demanding in order to reelect the incumbents. In particular, there will be government shutdown with positive probability in equilibrium. Gridlocks occur due to the imperfect information of voters and they constitute indeed an information revelation mechanism that improves electoral control in the second period.

Modelo para avaliação de desempenho do sistema de saúde municipal com foco nas ações da saúde materno-infantil da atenção básica por meio de indicadores sociais

O presente trabalho aborda o desempenho dos sistemas municipais de saúde, tendo como foco a saúde materno-infantil. Com o objetivo de apontar as possíveis fragilidades dos sistemas de saúde, especificamente daqueles em que a Atenção Primária (AP) é a principal ou exclusiva estratégia de atuação da gestão municipal, foi criado um modelo teórico de avaliação dos indicadores de saúde, denominado de ADS. Aplicado às cidades com população entre 14 mil e 35 mil habitantes, onde o sistema de saúde se baseia exclusivamente na política de AP, esse modelo foi construído por meio da técnica de consenso, com a formação de um grupo de 12 especialistas na área de saúde coletiva para definição e validação de critérios para análise dos sistemas. Testado na cidade de Iati, localizada no Agreste Meridional e distante 282 quilômetros da capital pernambucana, o ADS apontou fatores ambientais e socioeconômicos abaixo da média, além de vulnerabilidades da assistência materno-infantil que influenciam negativamente a situação de saúde do município. A avaliação verificou ainda desempenho insatisfatório no que diz respeito ao acompanhamento das crianças e gestantes por meio de consultas médicas (efetividade); assistência à criança (continuidade); cobertura de consultas em crianças e imunização de gestantes (acesso aos serviços da Atenção Primária); produtividade das ações realizadas pelos profissionais de saúde (eficiência) e capacidade de investigação dos óbitos infantis, qualidade dos registros e controle da sífilis em gestantes (vigilância à saúde). Também foi observada baixa alocação de investimentos em saúde em combinação com a carência de recursos humanos e materiais para prestar os serviços. Ao final da pesquisa, foi possível constatar a viabilidade de aplicação do modelo para planejamento das auditorias, avaliando o desempenho dos indicadores de saúde no âmbito municipal.

A search-theoretic explanation for the negative correlation between labor income and impatience

Lawrance (1991) has shown, through the estimation of consumption Euler equations, that subjective rates of impatience (time preference) in the U.S. are three to Öve percentage points higher for households with lower average labor incomes than for those with higher labor income. From a theoretical perspective, the sign of this correlation in a job-search model seems at Örst to be undetermined, since more impatient workers tend to accept wage o§ers that less impatient workers would not, thereby remaining less time unemployed. The main result of this paper is showing that, regardless of the existence of e§ects of opposite sign, and independently of the particular speciÖcations of the givens of the model, less impatient workers always end up, in the long run, with a higher average income. The result is based on the (unique) invariant Markov distribution of wages associated with the dynamic optimization problem solved by the consumers. An example is provided to illustrate the method.

Who is the cowboy in Washington?: beating google at their own game with neuroscience and cryptography

Who was the cowboy in Washington? What is the land of sushi? Most people would have answers to these questions readily available,yet, modern search engines, arguably the epitome of technology in finding answers to most questions, are completely unable to do so. It seems that people capture few information items to rapidly converge to a seemingly 'obvious' solution. We will study approaches for this problem, with two additional hard demands that constrain the space of possible theories: the sought model must be both psychologically and neuroscienti cally plausible. Building on top of the mathematical model of memory called Sparse Distributed Memory, we will see how some well-known methods in cryptography can point toward a promising, comprehensive, solution that preserves four crucial properties of human psychology.