Всего статей в данном разделе : 69
Опубликовано на портале: 25-11-2004David Myatt, Chris C. Wallace Games and Economic Behavior. 2004. Vol. 48. No. 1. P. 124-138.
Equilibrium selection in coordination games has generated a large literature. Kandori, Mailath and Rob (1993) and Young (1993) studied dynamic models of aggregate behaviour in which agents choose best responses to observations of population play. Crucially, infrequent mistakes (`mutations`) allow agents to take actions contrary to current trends and prevent initial configurations from determining long run play. An alternative approach is offered here: Harsanyian trembles are added to agents` payoffs so that with some probability it is optimal to act against the flow of play. The long run distribution of population behaviour is characterised - modes correspond to stable Bayesian Nash equilibria. Allowing the variance of payoff trembles to vanish, via a purification process, a single equilibrium is played almost always in the long run. Kandori et al and Young show that the number of contrarian actions required to escape an equilibrium determines selection; here, the likelihood that such actions are taken is of equal importance.
Agreeing to Disagree [статья]
Опубликовано на портале: 31-01-2007Robert J. Aumann Annals of Statistics. 1976. Vol. 4. No. 6. P. 1236-39.
Aumann (1976) put forward a formal definition of common knowledge and used it to prove that two "like minded" individuals cannot "agree to disagree" in the following sense. If they start from a common prior and update the probability of an event E (using Bayes' rule) on the basis of private information, then it cannot be common knowledge between them that individual 1 assigns probability p to E and individual 2 assigns probability q to E with p, which is not equal to q. In other words, if their posteriors of event E are common knowledge then they must coincide. Aumann's Agreement Theorem has given rise to a large literature which review in this paper. The results are classified according to whether they are probabilistic (Bayesian) or qualitative. Particular attention is paid to the issue of how to interpret the notion of Harsanyi consistency as a (local) property of belief hierarchies.
Опубликовано на портале: 30-01-2007Lawrence M. Ausubel American Economic Review. 2004. Vol. 94. No. 5. P. 1452-1475.
When bidders exhibit multi-unit demands, standard auction methods generally yield inefficient outcomes. This article proposes a new ascending-bid auction for homogeneous goods, such as Treasury bills or telecommunications spectrum. The auctioneer announces a price and bidders respond with quantities. Items are awarded at the current price whenever they are "clinched," and the price is incremented until the market clears. With private values, this (dynamic) auction yields the same outcome as the (sealed-bid) Vickrey auction, but has advantages of simplicity and privacy preservation. With interdependent values, this auction may retain efficiency, whereas the Vickrey auction suffers from a generalized Winner's Curse.
Опубликовано на портале: 30-01-2007Debraj Ray, Kaljan Chatterjee, Kunal Sengupta, Bhaskar Dutta Review of Economic Studies. 1993. Vol. 60. No. 2. P. 463-77.
The authors explore a sequential offers model of n-person coalitional bargaining with transferable utility and with time discounting. Their focus is on the efficiency properties of stationary equilibria of strictly superadditive games when the discount factor 'delta' is sufficiently large. It is shown that delay and the formation of inefficient subcoalitions can occur in equilibrium, the latter for some or all orders of proposer. However, efficient stationary equilibrium payoffs converge to a point in the core as 'delta' approaches one. Strict convexity is a sufficient condition for there to exist an efficient stationary equilibrium payoff vector for sufficiently high 'delta'.
Опубликовано на портале: 31-01-2007Motty Perry, Philip John Reny Econometrica. 1994. Vol. 62. No. 4. P. 795-817.
A noncooperative implementation of the core is provided for games with transferable utility. The implementation obtained here is meant to reflect the standard motivation for the core as closely as possible. In the model proposed, time is continuous. This idealized treatment of time is most amenable for capturing an essential feature of the core - there is always time to reject a noncore proposal before it is consumated.
Опубликовано на портале: 24-01-2007Andrew Weiss Journal of Political Economy. 1983. Vol. 91. No. 3. P. 420-442.
This paper presents a sorting model of education in with individuals are tested in school. By assuming that higher-ability individuals are more likely to succeed on a given test one can construct a sorting model of education that does not hinge on the more able having lower nonpecuniary costs of schooling. Nash equilibria always exist in this model (even with a continuum of types of individuals); however, some are "unreasonable." To eliminate these unreasonable Nash equilibria, more restrictive definitions of equilibrium are proposed. I also show that when schooling affects productivity - and therefore a worker's probability of passing the test--a sorting equilibrium may be characterized by too little investment in education. This paper extends the important work of Spence (1974), Stiglitz (1975), and Riley (1979a, 1979b) on sorting theories of education by modeling the educational choices of individuals in game-theoretic terms and making two assumptions: (1) individuals are not perfectly informed about their own productivity, and (2) individuals are tested upon their completion of schooling. I also combine the sorting and human capital analyses by allowing education to increase productivity and show that if education increases the productivity of workers as well as enabling the more able workers to sort themselves, these sorting effects may lead to underinvestment in education. This result contradicts the main normative result of screening models of education: If skills are hierarchical, so that if Joe is more productive than Jim at any job he is more productive at all jobs, there is overinvestment in schooling as workers use education to signal their abilities. Although in a pure sorting model education always leads to overinvestment in education while human capital models lead to optimal investment, when both effects are modeled there may be too little investment in education. This result holds even if the more able learn faster in school.
Опубликовано на портале: 22-03-2007Robert H. Porter RAND Journal of Economics. 1983. Vol. 14. No. 2. P. 301-314.
This article employs weekly time series data on the Joint Executive Committee railroad cartel from 1880 to 1886 to test empirically the proposition that observed prices reflected switches from collusive to noncooperative behavior. An equilibrium model of dynamic oligopoly with asymmetric firms, together with explicit functional form assumptions about costs and demand, determines the estimating equations and stochastic structure of the econometric model. The hypothesis that no switch took place, so that price and quantity movements were solely attributable to exogenous shifts in the demand and cost functions, is then tested against this alternative and rejected.
Опубликовано на портале: 31-01-2007Debraj Ray, Rakesh V. Vohra Games and Economic Behavior. 1999. Vol. 26. No. 2. P. 286-336.
Consider an environment with widespread externalities, and suppose that binding agreements can be written. We study coalition formation in such a setting. Our analysis proceeds by defining on a partition function an extensive-form bargaining game. We establish the existence of a stationary subgame perfect equilibrium for such a game. Our main results are concerned with the characterization of equilibrium coalition structures. We develop an algorithm that generates (under certain conditions) an equilibrium coalition structure. Our characterization results are especially sharp for symmetric partition functions. In particular, we provide a uniqueness theorem and apply our results to a Cournot oligopoly.
Auctions versus Negotiations [статья]
Опубликовано на портале: 30-01-2007Paul D. Klemperer, Jeremy I. Bulow American Economic Review. 1996. Vol. 86. No. 1. P. 180-94.
Which is the more profitable way to sell a company: an auction with no reserve price or an optimally structured negotiation with one less bidder? The authors show, under reasonable assumptions, that the auction is always preferable when bidders' signals are independent. For affiliated signals, the result holds under certain restrictions on the seller's choice of negotiating mechanism. The result suggests that the value of negotiating skill is small relative to the value of additional competition. The paper also shows how the analogies between monopoly theory and auction theory can help derive new results in auction theory.
Опубликовано на портале: 30-01-2007Muhamet Yildiz Econometrica. 2003. Vol. 71. No. 3. P. 793-811.
In sequential bargaining models without outside options, each player's bargaining power is ultimately determined by which player will make an offer and when. This paper analyzes a sequential bargaining model in which players may hold different beliefs about which player will make an offer and when. Excessive optimism about making offers in the future can cause delays in agreement. The main result states that, despite this, if players will remain sufficiently optimistic for a sufficiently long future, then in equilibrium they will agree immediately. This result is also extended to other canonical models of optimism.
Опубликовано на портале: 12-05-2004Leo K. Simon Review of Economic Studies. 1984. Vol. 51. P. 209-230.
Presents a study which developed a game-theoretic model of a pure exchange, monetary economy in which buyers and sellers announce both quantities and prices. Motivation and outline of the model; Similarities and differences between the model and that of Bertrand's; Components of the strategic market game.
Bidding Rings [статья]
Опубликовано на портале: 31-01-2007John McMillan, R. Preston McAfee American Economic Review. 1992. Vol. 82. No. 3. P. 579-99.
The authors characterize coordinated bidding strategies in two cases: a weak cartel, in which the bidders cannot make side-payments; and a strong cartel, in which the cartel members can exclude new entrants and can make transfer payments. The weak cartel can do no better than have its members submit identical bids. The strong cartel in effect reauctions the good among the cartel members.
Cheap Talk [статья]
Опубликовано на портале: 31-01-2007Joseph Farrel, Matthew Rabin Journal of Economic Perspectives. 1996. Vol. 10. No. 3. P. 103-118.
Economists often ask how private information is shared through markets, costly signaling, and other mechanisms. Yet most information sharing is done through ordinary, informal talk. Economists are inconsistent in their view of such 'cheap talk': sometimes it is supposed that communication generally leads to efficient equilibria; other times it is supposed that since 'talk is cheap,' it is never credible. The authors think both views are wrong. In this paper, they describe what some recent research in game theory teaches about when people will convey private information by cheap talk.
Common Agency [статья]
Опубликовано на портале: 31-01-2007B. Douglas Bernheim, Michael D. Whinston Econometrica. 1986. Vol. 54. No. 4. P. 923-942.
We extend the principal-agent framework with risk-neutral principals to situations in which several principals simultaneously and independently attempt to influence a common agent. We show that implementation is, in the aggregate, always efficient (cost-minimizing), and that noncooperative behavior induces an efficient (potentially second-best) action choice if and only if collusion among the principals would implement the first-best action at the first-best level of cost. We also investigate the existence of equilibria, the distribution of net rewards among principals, the characteristics of actions chosen in inefficient equilibria, and potential institutional remedies for welfare losses induced by noncooperative behavior.
Contracting with Externalities [статья]
Опубликовано на портале: 31-01-2007Ilya R. Segal Quarterly Journal of Economics. 1999. Vol. 114. No. 2. P. 337-388.
The paper studies inefficiencies arising in contracting between one principal and N agents when the utility of each agent depends on all agents' trades with the principal. When the principal commits to a set of publicly observable bilateral contract offers, the arising inefficiency is due entirely to the externalities imposed on non-signers. In contrast, when the principal's offers are privately observed, the distortion is due to the externalities given agents' equilibrium trades. Comparison of the two externalities determines the relative efficiency of the two contracting regimes. In both cases, we show that when N is large, each agent can be treated as non-pivotal, provided that appropriate continuity assumptions are satisfied. We also study the case in which the principal can condition each agent's trade on other agents' messages. We characterize the set of such mechanisms in which each agent's participation is voluntary. When the principal can commit to any such mechanism, she implements the first-best outcome, while threatening each deviator with the harshest possible punishment. However, in the presence of noise that goes to zero slower than N goes to infinity, in the limit we obtain a (generally inefficient) outcome in which each agent feels non-pivotal.