Mixed oligopoly in education

This paper studies oligopolistic competition in education markets when schools can be private and public and when the quality of education depends on ìpeer groupî e§ects. In the Örst stage of our game schools set their quality and in the second stage they Öx their tuition fees. We examine how the (subgame perfect Nash) equilibrium allocation (qualities, tuition fees and welfare) is a§ected by the presence of public schools and by their relative position in the quality range. When there are no peer group e§ects, e¢ ciency is achieved when (at least) all but one school are public. In particular in the two school case, the impact of a public school is spectacular as we go from a setting of extreme di§erentiation to an e¢ cient allocation. However, in the three school case, a single public school will lower welfare compared to the private equilibrium. We then introduce a peer group e§ect which, for any given school is determined by its student with the highest ability. These PGE do have a signiÖcant impact on the results. The mixed equilibrium is now never e¢ cient. However, welfare continues to be improved if all but one school are public. Overall, the presence of PGE reduces the e§ectiveness of public schools as regulatory tool in an otherwise private education sector.

An experiment on subjective game valuations

We report experimental results on a prisoners' dilemma implemented in a way which allows us to elicit incentive−compatible valuations of the game. We test the hypothesis that players' valuations coincide with their Nash equilibrium earnings. Our results offer significantly less support for this hypothesis than for the prediction of Dominant Strategy (DS) play.

Bargaining over strategies of non-cooperative games

We propose a bargaining process supergame over the strategies to play in a non-cooperative game. The agreement reached by players at the end of the bargaining process is the strategy profile that they will play in the original non-cooperative game. We analyze the subgame perfect equilibria of this supergame, and its implications on the original game. We discuss existence, uniqueness, and efficiency of the agreement reachable through this bargaining process. We illustrate the consequences of applying such a process to several common two-player non-cooperative games: the Prisoner’s Dilemma, the Hawk-Dove Game, the Trust Game, and the Ultimatum Game. In each of them, the proposed bargaining process gives rise to Pareto-efficient agreements that are typically different from the Nash equilibrium of the original games.

Marine protected areas in artisanal fisheries: a spatial bio-economic model based on observations in Costa Rica and Tanzania

In many lower-income countries, the establishment of marine protected areas (MPAs) involves significant opportunity costs for artisanal fishers, reflected in changes in how they allocate their labor in response to the MPA. The resource economics literature rarely addresses such labor allocation decisions of artisanal fishers and how, in turn, these contribute to the impact of MPAs on fish stocks, yield, and income. This paper develops a spatial bio-economic model of a fishery adjacent to a village of people who allocate their labor between fishing and on-shore wage opportunities to establish a spatial Nash equilibrium at a steady state fish stock in response to various locations for no-take zone MPAs and managed access MPAs. Villagers’ fishing location decisions are based on distance costs, fishing returns, and wages. Here, the MPA location determines its impact on fish stocks, fish yield, and villager income due to distance costs, congestion, and fish dispersal. Incorporating wage labor opportunities into the framework allows examination of the MPA’s impact on rural incomes, with results determining that win-wins between yield and stocks occur in very different MPA locations than do win-wins between income and stocks. Similarly, villagers in a high-wage setting face a lower burden from MPAs than do those in low-wage settings. Motivated by issues of central importance in Tanzania and Costa Rica, we impose various policies on this fishery – location specific no-take zones, increasing on-shore wages, and restricting MPA access to a subset of villagers – to analyze the impact of an MPA on fish stocks and rural incomes in such settings.

Divide-the-Dollar game revisited

In the Divide-the-Dollar (DD) game, two players simultaneously make demands to divide a dollar. Each player receives his demand if the sum of the demands does not exceed one, a payoff of zero otherwise. Note that, in the latter case, both parties are punished severely. A major setback of DD is that each division of the dollar is a Nash equilibrium outcome. Observe that, when the sum of the two demands x and y exceeds one, it is as if Player 1's demand x (or his offer (1−x) to Player 2) suggests that Player 2 agrees to λx < 1 times his demand y so that Player 1's demand and Player 2's modified demand add up to exactly one; similarly, Player 2's demand y (or his offer (1−y) to Player 1) suggests that Player 1 agrees to λyx so that λyx+y = 1. Considering this fact, we change DD's payoff assignment rule when the sum of the demands exceeds one; here in this case, each player's payoff becomes his demand times his λ; i.e., each player has to make the sacrifice that he asks his opponent to make. We show that this modified version of DD has an iterated strict dominant strategy equilibrium in which each player makes the egalitarian demand 1/2. We also provide a natural N-person generalization of this procedure.

Contests with the probability of a draw : a stochastic foundation

This article proposes a stochastic foundation for the contest success function (CSF for short) with a richer structure on the set of possible outcomes of the contest. Specifically, the analysis allows for the possibility of a draw, so that no contestant can claim a victory over all other players. Under plausible conditions, this article not only discovers new functional forms of CSFs, but also shows the newly derived CSFs have very different properties in equilibrium to those of conventional CSFs. For example, in contrast to the CSFs discussed in the contest literature, which always generate a unique pure strategy Nash equilibrium, the newly discovered CSFs admit the possibility of multiple equilibria.

Oligopolistic competition under knightian uncertainty

This artic/e applies a theorem of Nash equilibrium under uncertainty (Dow & Werlang, 1994) to the classic Coumot model of oligopolistic competition. It shows, in particular, how one can map all Coumot equilibrium (which includes the monopoly and the null solutions) with only a function of uncertainty aversion coefficients of producers. The effect of variations in these parameters over the equilibrium quantities are studied, also assuming exogenous increases in the number of matching firms in the game. The Cournot solutions under uncertainty are compared with the monopolistic one. It shows principally that there is an uncertainty aversion level in the industry such that every aversion coefficient beyond it induces firms to produce an aggregate output smaller than the monopoly output. At the end of the artic/e equilibrium solutions are specialized for Linear Demand and for Coumot duopoly. Equilibrium analysis in the symmetric case allows to identify the uncertainty aversion coefficient for the whole industry as a proportional lack of information cost which would be conveyed by market price in the perfect competition case (Lerner Index).

The Bayesian Foundations of solution concepts of games

We transform a non co-operati ve game into a -Bayesian decision problem for each player where the uncertainty faced by a player is the strategy choices of the other players, the pr iors of other players on the choice of other players, the priors over priors and so on.We provide a complete characterization between the extent of knowledge about the rationality of players and their ability to successfulIy eliminate strategies which are not best responses. This paper therefore provides the informational foundations of iteratively unàominated strategies and rationalizable strategic behavior (Bernheim (1984) and Pearce (1984». Moreover, sufficient condi tions are also found for Nash equilibrium behavior. We also provide Aumann's (1985) results on correlated equilibria .

A gestão do processo de negociação complexa: uma avaliação da 5ª Conferência Ministerial da Organização Mundial do Comércio - OMC, em Cancun, México

Pretende-se no presente trabalho avaliar a gestão do processo de negociação complexa da 5ª Conferência Ministerial da Organização Mundial do Comércio em Cancún, ocorrida entre os dias 10 e 14 de setembro de 2003, no México, apontando os problemas e questões que resultaram no colapso de um possível acordo. O futuro da OMC é incerto e mudanças traumáticas sofridas por muitos países que vivem sob as regras da OMC indicam que alguma coisa na OMC terá que mudar, principalmente nos processos de negociação complexa, de forma que a integridade da organização não seja comprometida. Buscou-se respostas na análise e avaliação da gestão do processo de negociação, estudando e pesquisando os conceitos de barganha posicional, detalhando o processo de negociação baseado em princípios, explorando em profundidade o estado da arte para gestão de conversas difíceis. Dissecando a questão dos conflitos e das coalizões, mostrando a dificuldade existente na resolução de disputas públicas e no uso de instrumentos para quebrar o impasse nas negociações buscou-se estabelecer o instrumental teórico que possibilitasse aprofundar o diagnóstico da situação atual na OMC. Como recomendação explorou-se a avaliação de conflitos, com base na eficiência - teoria dos jogos-, justiça e na eqüidade, a melhor forma de negociação baseada em princípios, de gestão de público demandante, no diálogo dos multistakeholders, a importância das conversas informais paralelas, o ambiente da complexidade e a visão ampla que proporciona o enfoque do funcionamento de sistemas decisórios autopoiéticos.

Income and bargaining effects on education and health

In this paper, we examine the impacts of the reform in the rural pension system in Brazil in 1991 on schooling and health indicators. In addition, we use the reform to investigate the validity of the unitary model of household allocation by testing if there were uneven impacts on those indicators depending on the gender of the recipient. The main conclusion of the paper is that the reform had significantly positive effects on the outcomes of interest, especially on those co-residing with a male pensioner, indicating that the unitary model is not a well-specified framework to understand family allocation decisions. The highest impacts were on school attendance for boys, literacy for girls and illness for middle-age people. We explore a collective model as defined by Chiappori (1992) as one possible alternative representation for the decision-making process of the poor rural Brazilian families. In the cooperative Nash equilibrium, the reform effects can be divided into two pieces: a direct income effect and bargaining power effect. The data support the existence of these two different effects

Estimação de parâmetros de demanda e oferta em mercados de produtos diferenciados

Este trabalho tem por objetivo discutir detalhadamente o desenvolvimento de métodos de estimação de parâmetros de demanda e oferta em mercados de produtos diferenciados. As técnicas apresentadas consideram explicitamente a endogeneidade dos preços e podem ser aplicadas a diferentes tipos de indústrias. O sistema de demandas de mercado é derivado a partir de modelos de escolha discreta descrevendo o comportamento do consumidor. Esse sistema é então combinado com hipóteses sobre as funções custo e sobre o comportamento de determinação dos preços por parte das firmas para gerar preços e quantidades de equilíbrio. Os parâmetros a ser estimados são os que determinam os custos marginais das firmas e a distribuição dos gostos dos consumidores. Essa distribuição determina elasticidades e estas, combinadas com o custo marginal e com uma hipótese de equilíbrio de Nash na determinação de preços, determinam preços de equilíbrio. Essas elasticidades e parâmetros de custo desempenham um papel central em análises de questões descritivas e de mudanças no ambiente do mercado sob análise.

Hybrid Auctions II: Experimental Evidence

In this paper we report the results of an experiment designed to examine the properties of a hybrid auction - a Dutch-Vickrey auction, that combines a sealed bid …rst-price auction with a sealed bid second-price auction. This auction mechanism shares some important features with that used in the sale of the companies constituted through the partial division of the Telebras System - the government-owned Telecom holding in Brazil. We designed an experiment where individuals participate in a sequence of independent …rst-price auctions followed by a sequence of hybrid auctions. Several conclusions emerged from this experimental study. First, ex-post e¢ciency was achieved overwhelmingly by the hybrid auctions. Secondly, although overbidding (with respect to the risk-neutral Bayesian Nash equilibrium) was a regular feature of participants’ bidding behavior in the …rst-price auctions — as it is commonly reported in most experimental studies of …rst-price auctions, it was less frequent in the hybrid auctions. By calibrating the results to allow for risk-averse behavior we were able to account for a signi…cant part of the overbidding. Finally, we compared the revenue generated by the hybrid auction with that generated by a standard …rst-price sealed bid auction and the results were ambiguous.

Uma barreira à entrada não tão inocente

Em teorias de oligop olio baseadas em Equil brios de Nash e conceitos derivados, livre entrada e associada a coexist^encia de uma ou mais rmas. Por outro lado, teorias de monop olio que tentam explicar a aus^encia de concorrentes em ambientes com livre entrada n~ao se baseiam em equil brios de Teoria dos Jogos. Neste trabalho, usando um arcabou co de Teoria dos Jogos, apresento exemplos em que randomiza c~ao entre pre cos de monop olio e uma nova poss vel explica c~ao para a exist^encia de um monopolista com lucros positivos quando h a livre entrada. S~ao constru dos modelos onde, devido a multidimensionalidade dos bens e heterogeneidade dos consumidores, existe mais de um pre co de monop olio, possibilitando randomiza c~ao em equil brio.

Precificação em orquestradores de informação: maximizando redes estáveis

Em redes de inovação baseadas em trocas de informação, o agente orquestrador se apropria das informações dos atores periféricos, gera inovação e distribui em forma de valor agregado. É sua função promover a estabilidade na rede fazendo com que a mesma tenha taxas não negativas de crescimento. Nos mercados de análise de crédito e fraude, por exemplo, ou bureaus funcionam como agentes orquestradores, concentrando as informações históricas da população que são provenientes de seus clientes e fornecendo produtos que auxiliam na tomada de decisão. Assumindo todas as empresas do ecossistema como agentes racionais, a teoria dos jogos se torna uma ferramenta apropriada para o estudo da precificação dos produtos como mecanismo de promoção da estabilidade da rede. Este trabalho busca identificar a relação de diferentes estruturas de precificação promovidas pelo agente orquestrador com a estabilidade e eficiência da rede de inovação. Uma vez que o poder da rede se dá pela força conjunta de seus membros, a inovação por esta gerada varia de acordo com a decisão isolada de cada agente periférico de contratar o agente orquestrador ao preço por ele estipulado. Através da definição de um jogo teórico simplificado onde diferentes agentes decidem conectar-se ou não à rede nas diferentes estruturas de preços estipuladas pelo agente orquestrador, o estudo analisa as condições de equilíbrio conclui que o equilíbrio de Nash implica em um cenário de estabilidade da rede. Uma conclusão é que, para maximizar o poder de inovação da rede, o preço a ser pago por cada agente para fazer uso da rede deve ser diretamente proporcional ao benefício financeiro auferido pela inovação gerada pela mesma. O estudo apresenta ainda uma simulação computacional de um mercado fictício para demonstração numérica dos efeitos observados. Através das conclusões obtidas, o trabalho cobre uma lacuna da literatura de redes de inovação com agentes orquestradores monopolistas em termos de precificação do uso da rede, servindo de subsídio de tomadores de decisão quando da oferta ou demanda dos serviços da rede.