Resultados uniformemente seguros e equilíbrio de Nash em jogos compactos

Nós introduzimos uma condição, resultados uniformemente seguros, para jogos compactos e resultados (“payoffs”) limitados e mensur´aveis nas estrat´egias. Demonstramos que se um jogo compacto tem resultados uniformemente seguros, ent˜ao sua extens˜ao mista tem resultados seguros.

Public debt sustainability and endogenous seignorage in Brazil: time-series evidence from 1947-92

Using national accounts data for the revenue-GDP and expenditure GDP ratios from 1947 to 1992, we examine two central issues in public finance. First, was the path of public debt sustainable during this period? Second, if debt is sustainable, how has the government historically balanced the budget after hocks to either revenues or expenditures? The results show that (i) public deficit is stationary (bounded asymptotic variance), with the budget in Brazil being balanced almost entirely through changes in taxes, regardless of the cause of the initial imbalance. Expenditures are weakly exogenous, but tax revenues are not;(ii) a rational Brazilian consumer can have a behavior consistent with Ricardian Equivalence (iii) seignorage revenues are critical to restore intertemporal budget equilibrium, since, when we exclude them from total revenues, debt is not sustainable in econometric tests.

Imposto inflacionário e transferências inflacionárias no Brasil: 1947-2003

Este artigo atualiza, atÈ 2003, a sÈrie 1947-1992 de imposto in- áacion·rio, transferÍncias ináacion·rias para os bancos comerciais e transferÍncia ináacion·rias totais, anteriormente publicada em Cysne (1994) e Simonsen e Cysne (1995).

Nash equilibrium under knightian uncertainty: breaking down backward induction (extensively revised version)

We define Nash equilibrium for two-person normal form games in the presence of uncertainty, in the sense of Knight(1921). We use the fonna1iution of uncertainty due to Schmeidler and Gilboa. We show tbat there exist Nash equilibria for any degree of uncertainty, as measured by the uncertainty aversion (Dow anel Wer1ang(l992a». We show by example tbat prudent behaviour (maxmin) can be obtained as an outcome even when it is not rationaliuble in the usual sense. Next, we break down backward industion in the twice repeated prisoner's dilemma. We link these results with those on cooperation in the finitely repeated prisoner's dilemma obtained by Kreps-Milgrom-Roberts-Wdson(1982), and withthe 1iterature on epistemological conditions underlying Nash equilibrium. The knowledge notion implicit in this mode1 of equilibrium does not display logical omniscience.

Nash equilibrium under knightian uncertainty: breaking-down backward induction

We present two alternative definitions of Nash equilibrium for two person games in the presence af uncertainty, in the sense of Knight. We use the formalization of uncertainty due to Schmeidler and Gilboa. We show that, with one of the definitions, prudent behaviour (maxmin) can be obtained as an outcome even when it is not rationalizable in the usual sense. Most striking is that with the Same definition we break down backward induction in the twice repeated prisoner's dilemma. We also link these results with the Kreps-Milgrom-Roberts-Wilson explanation of cooperation in the finitely repeated prisoner's dilemma.

A comment on "Rational learning lead to nash equilibrium" by professors Ehud Kalai and Ehud Lehrer

Kalai and Lebrer (93a, b) have recently show that for the case of infinitely repeated games, a coordination assumption on beliefs and optimal strategies ensures convergence to Nash equilibrium. In this paper, we show that for the case of repeated games with long (but finite) horizon, their condition does not imply approximate Nash equilibrium play. Recently Kalai and Lehrer (93a, b) proved that a coordination assumption on beliefs and optimal strategies, ensures that pIayers of an infinitely repeated game eventually pIay 'E-close" to an E-Nash equilibrium. Their coordination assumption requires that if players believes that certain set of outcomes have positive probability then it must be the case that this set of outcomes have, in fact, positive probability. This coordination assumption is called absolute continuity. For the case of finitely repeated games, the absolute continuity assumption is a quite innocuous assumption that just ensures that pIayers' can revise their priors by Bayes' Law. However, for the case of infinitely repeated games, the absolute continuity assumption is a stronger requirement because it also refers to events that can never be observed in finite time.

Análise da contribuição da revista de administração (1947-1992) na evolução do campo de conhecimento em administração pública

O trabalho analisa a evolução do campo de conhecimento em Administração Pública no Brasil com base em trabalho empírico realizado junto a duas revistas especializadas: Revista de Administração de Empresas (RAE) - (1961-1992) e Revista de Administração (RAE) - (1947-1992). Os artigos nelas publicados foram classificados de acordo com seu locus (objeto empírico analisado) e seu focus (instrumental teórico utilizado).

Public debt sustainability and endogenous seigniorage in Brazil: time-series evidence from 1947-92: revised version

Using national accounts data for the revenue-GDP and expenditureGDP ratios from 1947 to 1992, we examine three central issues in public finance. First, was the path of public debt sustainable during this period? Second, if debt is sustainable, how has the government historically balanced the budget after shocks to either revenues or expenditures? Third, are expenditures exogenous? The results show that (i) public deficit is stationary (bounded asymptotic variance), with the budget in Brazil being balanced almost entirely through changes in taxes, regardless of the cause of the initial imbalance. Expenditures are weakly exogenous, but tax revenues are not; (ii) the behavior of a rational Brazilian consumer may be consistent with Ricardian Equivalence; (iii) seigniorage revenues are critical to restore intertemporal budget equilibrium, since, when we exclude them from total revenues, debt is not sustainable in econometric tests.

A notion of subgame perfect Nash equilibrium under knightian uncertainty

We define a subgame perfect Nash equilibrium under Knightian uncertainty for two players, by means of a recursive backward induction procedure. We prove an extension of the Zermelo-von Neumann-Kuhn Theorem for games of perfect information, i. e., that the recursive procedure generates a Nash equilibrium under uncertainty (Dow and Werlang(1994)) of the whole game. We apply the notion for two well known games: the chain store and the centipede. On the one hand, we show that subgame perfection under Knightian uncertainty explains the chain store paradox in a one shot version. On the other hand, we show that subgame perfection under uncertainty does not account for the leaving behavior observed in the centipede game. This is in contrast to Dow, Orioli and Werlang(1996) where we explain by means of Nash equilibria under uncertainty (but not subgame perfect) the experiments of McKelvey and Palfrey(1992). Finally, we show that there may be nontrivial subgame perfect equilibria under uncertainty in more complex extensive form games, as in the case of the finitely repeated prisoner's dilemma, which accounts for cooperation in early stages of the game.

Mobilidade de capitais e movimentos da conta corrente do Brasil: 1947-1997

Com base na análise histórica da economia brasileira nas últimas décadas, poder-se-ia supor que sejam expressivas as restrições aos movimentos internacionais de capitais. Para analisar essa questão, usa-se o modelo intertemporal da conta corrente, testando as suas proposições básicas com dados econômicos brasileiros (perfeita mobilidade de capitais sob a Teoria da Renda Permanente). Para testar o modelo, trabalha-se com a técnica econométrica desenvolvida por Campbell (1987) e Campbell e Shiller (1987), aplicáveis a teorias de valor presente, onde a conta corrente é vista como valor presente das mudanças do produto líquido. Os resultados encontrados revelam que o modelo é rejeitado para os dados brasileiros, uma vez que nem todas as proposições testáveis são confirmadas. Isto mostra a inexistência de plena mobilidade de capitais, o que corrobora as suspeitas levantadas a partir da análise histórica. No entanto, foram constatados elevado grau de mobilidade de capitais e significativo fluxo de capitais especulativos, pois a série de conta corrente estimada de acordo com o modelo mostra-se menos volátil que a série observada na economia brasileira.

PIB trimestral: proposta metodológica e resultados para o período 1947-79

Este trabalho apresenta uma metodologia para o cálculo do PIB trimestral a preços constantes nos anos anteriores a 1980, quando o IBGE passou a calcular esse indicador para o Brasil, e apresenta os resultados de sua aplicação aos anos de 1947 a 1980. Para a estimação do indicador do PIB trimestral construiu-se primeiramente uma base de dados composta por séries fortemente associadas ao nível de atividade econômica nacional depois de 1980 e que também estivessem disponíveis em frequência mensal ou trimestral no período 1947-80. Em seguida, aplicou-se às séries dessa base de dados o método do filtro de Kalman com a restrição de que a cada ano a taxa de crescimento das médias do PIB trimestral obtido após a estimação seja igual à variação da série anual calculada pelas Contas Nacionais.

A notion of subgame perfect nash equilibrium under knightian uncertainty

We define a subgame perfect Nash equilibrium under Knightian uncertainty for two players, by means of a recursive backward induction procedure. We prove an extension of the Zermelo-von Neumann-Kuhn Theorem for games of perfect information, i. e., that the recursive procedure generates a Nash equilibrium under uncertainty (Dow and Werlang(1994)) of the whole game. We apply the notion for two well known games: the chain store and the centipede. On the one hand, we show that subgame perfection under Knightian uncertainty explains the chain store paradox in a one shot version. On the other hand, we show that subgame perfection under uncertainty does not account for the leaving behavior observed in the centipede game. This is in contrast to Dow, Orioli and Werlang(1996) where we explain by means of Nash equilibria under uncertainty (but not subgame perfect) the experiments of McKelvey and Palfrey(1992). Finally, we show that there may be nontrivial subgame perfect equilibria under uncertainty in more complex extensive form games, as in the case of the finitely repeated prisoner's dilemma, which accounts for cooperation in early stages of the game .