
on Microeconomics 
By:  Yuichi Yamamoto (Department of Economics, University of Pennsylvania) 
Abstract:  We investigate whether two players in a longrun relationship can maintain cooperation when the details of the underlying game are unknown. Specifically, we consider a new class of repeated games with private monitoring, where an unobservable state of the world influences the payoff functions and/or the monitoring structure. Each player privately learns the state over time, but cannot observe what the opponent learns. We show that there are robust equilibria where players eventually obtain payoffs as if the true state were common knowledge and players played a “belieffree” equilibrium. The result is applied to various examples, including secret pricecutting with unknown demand. 
Keywords:  repeated game, private monitoring, incomplete information, belieffree equilibrium, expost equilibrium, individual learning 
JEL:  C72 C73 
Date:  2012–11–10 
URL:  http://d.repec.org/n?u=RePEc:pen:papers:12044&r=mic 
By:  Andrew Monaco (Department of Economics, Colgate University); Tarun Sabarwal (Department of Economics, University of Kansas) 
Abstract:  This paper studies games with both strategic substitutes and strategic complements, and more generally, games with strategic heterogeneity (GSH). Such games may behave differ ently from either games with strategic complements or games with strategic substitutes. Under mild assumptions (on one or two players only), the equilibrium set in a GSH is totally unordered (no two equilibria are comparable in the standard product order). Moreover, under mild assumptions (on one player only), parameterized GSH do not allow decreasing equilibrium selections. In general, this cannot be strengthened to conclude in creasing selections. Monotone comparative statics results are presented for games in which some players exhibit strategic substitutes and others exhibit strategic complements. For twoplayer games with linearly ordered strategy spaces, there is a characterization. More generally, there are sufficient conditions. The conditions apply only to players exhibiting strategic substitutes; no conditions are needed for players with strategic complements. Several examples highlight the results. 
Keywords:  Lattice games, strategic complements, strategic substitutes, strategic hetergeneity, equilibrium set, monotone comparative statics 
JEL:  C70 C72 
Date:  2012–11 
URL:  http://d.repec.org/n?u=RePEc:kan:wpaper:201240&r=mic 
By:  Laruelle, Annick; Iñarra García, María Elena; Zuazo Garín, Peio 
Abstract:  We assume that 2 x 2 matrix games are publicly known and that players perceive a dichotomous characteristic on their opponents which defines two types for each player. In turn, each type has beliefs concerning her opponent's types, and payoffs are assumed to be typeindependent. We analyze whether the mere possibility of different types playing different strategies generates discriminatory equilibria. Given a specific information structure we find that in equilibrium a player discriminates between her types if and only if her opponent does so. We also find that for dominant solvable 2x2 games no discriminatory equilibrium exists, while under different conditions of concordance between players' beliefs discrimination appears for coordination and for competitive games. A complete characterization of the set of Bayesian equilibria is provided. 
Keywords:  incomplete information, 2x2 matrix games 
JEL:  C72 
Date:  2012–10–23 
URL:  http://d.repec.org/n?u=RePEc:ehu:ikerla:9099&r=mic 
By:  Rida Laraki (Ecole Polytechnique  Ecole Polytechnique, IMJ  Institut de Mathématiques de Jussieu  CNRS : UMR7586  Université Paris VI  Pierre et Marie Curie  Université Paris VII  Paris Diderot); Eilon Solan (School of Mathematical Sciences [Tel Aviv]  Raymond and Beverly Sackler Faculty of Exact Sciences) 
Abstract:  We prove that every twoplayer nonzerosum Dynkin game in continuous time admits an "epsilon" equilibrium in randomized stopping times. We provide a condition that ensures the existence of an "epsilon" equilibrium in nonrandomized stopping times. 
Keywords:  Dynkin games, stopping games, equilibrium, stochastic analysis, continuous time. 
Date:  2012–11–19 
URL:  http://d.repec.org/n?u=RePEc:hal:wpaper:hal00753508&r=mic 
By:  Jeanne Hagenbach (Department of Economics, Ecole Polytechnique  CNRS : UMR7176  Polytechnique  X); Frédéric Koessler (PSE  ParisJourdan Sciences Economiques  CNRS : UMR8545  Ecole des Hautes Etudes en Sciences Sociales (EHESS)  Ecole des Ponts ParisTech  Ecole Normale Supérieure de Paris  ENS Paris); Eduardo PerezRichet (Department of Economics, Ecole Polytechnique  CNRS : UMR7176  Polytechnique  X) 
Abstract:  This article asks when communication with certi able information leads to complete information sharing. We consider Bayesian games augmented by a preplay communication phase in which announcements are made publicly. We characterize the augmented games in which there exists a full disclosure sequential equilibrium with extremal beliefs (i.e., any deviation is attributed to a single type of the deviator). This characterization enables us to provide di erent sets of su cient conditions for full information disclosure that encompass and extend all known results in the literature, and are easily applicable. We use these conditions to obtain new insights in sendersreceiver games, games with strategic complementarities, and voting with deliberation. 
Keywords:  Strategic Communication; Hard Information; Information Disclosure; Masquerade Relation; Belief Consistency; Single Crossing Di erences; Supermodular Games 
Date:  2012–11–19 
URL:  http://d.repec.org/n?u=RePEc:hal:psewpa:hal00753473&r=mic 
By:  Nejat Anbarci; Chingjen Sun 
Abstract:  This article proposes a simple Nash program. Both our axiomatic characterization and our noncooperative procedure consider each distinct asymmetric and symmetric Nash solution. Our noncooperative procedure is a generalization of the simplest known sequential Nash demand game analyzed by Rubinstein, Safra and Thomson (1992). We then provide the simplest known axiomatic characterization of the class of asymmetric Nash solutions, in which we use only Nash’s crucial Independence of Irrelevant Alternatives axiom and an asymmetric modification of the wellknown Midpoint Domination axiom. 
Keywords:  Asymmetric Nash bargaining solutions, Nash program, axiomatic characterization, noncooperative foundations, economics of search. 
JEL:  C78 D74 
Date:  2012–11–17 
URL:  http://d.repec.org/n?u=RePEc:dkn:econwp:eco_2012_9&r=mic 
By:  Hitoshi Matsushima (Faculty of Economics, University of Tokyo) 
Abstract:  We incorporate social influence into implementation theory, and highlight the manner in which an informed agent feels guilty with regard to disobeying an uninformed principal's wishes. The degree of this feeling depends on the agent's expectation of others' behavioral modes. We demonstrate a method of process manipulation, through which the principal employs psychological tactics for incentivizing agents to announce information in keeping with his/her wishes. We indicate that with a version of incentive compatibility, the principal can implement any alternative that he/she wishes as the unique Nash equilibrium without employing any contractual devices. Each agent's psychological cost would be negligible. 
Date:  2012–11 
URL:  http://d.repec.org/n?u=RePEc:tky:fseres:2012cf870&r=mic 
By:  Xu, Yongsheng; Yoshihara, Naoki 
Abstract:  Conditions α and β are two wellknown rationality conditions in the theory of rational choice. This paper examines the implications of weaker versions of these two rationality conditions in the context of solutions to nonconvex bargaining problems. It is shown that, together with the standard axioms of efficiency and strict individual rationality, they imply rationalizability of solutions to nonconvex bargaining problems. We then characterize asymmetric Nash solutions by imposing a continuity and the scale invariance requirements. These results make a further connection between solutions to nonconvex bargaining problems and rationalizability of choice function in the theory of rational choice. 
JEL:  C71 C78 D63 D71 
Date:  2012–11 
URL:  http://d.repec.org/n?u=RePEc:hit:hituec:580&r=mic 
By:  Nejat Anbarci; Chingjen Sun 
Abstract:  Most reallife bargaining is resolved gradually. During this process parties reach intermediate agreements. These intermediate agreements serve as disagreement points in subsequent rounds. We identify robustness criteria which are satisfied by three prominent bargaining solutions, the Nash, Proportional (and as a special case to the Egalitarian solution) and Discrete Raiffa solutions. We show that the .robustness of intermediate agreements. plus additional wellknown and plausible axioms, provide novel axiomatizations of the abovementioned solutions. Hence, we provide a unified framework for comparing these solutions’ bargaining theories. 
Keywords:  Nash’s bargaining problem, robustness, intermediate agreements, the Discrete Raiffa solution, the Nash solution, Proportional solutions. 
JEL:  C78 D74 
Date:  2012–11–16 
URL:  http://d.repec.org/n?u=RePEc:dkn:econwp:eco_2012_7&r=mic 
By:  Ekeland, Ivar; Galichon, Alfred 
Abstract:  This paper exhibits a duality between the theory of revealed preference of Afriat and the housing allocation problem of Shapley and Scarf. In particular, it is shown that Afriat’s theorem can be interpreted as a second welfare theorem in the housing problem. Using this duality, the revealed preference problem is connected to an optimal assignment problem, and a geometrical characterization of the rationalizability of experiment data is given. This allows in turn to give new indices of rationalizability of the data and to define weaker notions of rationalizability, in the spirit of Afriat’s efficiency index. 
Keywords:  Revealed preferences; Afriat’s theorem; Optimal assignments; Indivisible allocations; 
JEL:  D11 C60 C78 
Date:  2012 
URL:  http://d.repec.org/n?u=RePEc:ner:dauphi:urn:hdl:123456789/10574&r=mic 
By:  Aggey Semenov (Department of Economics, University of Ottawa, 120 University St., Ottawa,Ontario) 
Abstract:  We consider a delegation problem with a biased and potentially uninformed agent when the principal cannot use monetary payments. If the bias between the principal and the agent is large then the optimal delegation set is an interval. When the bias is small or medium the optimal delegation set is no longer connected. It can be one of two types: 1) with an interval and low option, 2) with two intervals. In all cases the agent has less discretion. However, in the case of medium bias the principal delegates in a wider range than in the case of an informed agent 
Keywords:  energy; Information, bias, noninformed agent, delegation set 
JEL:  D82 D86 
Date:  2012 
URL:  http://d.repec.org/n?u=RePEc:ott:wpaper:1215e&r=mic 
By:  Andrea Repetto (Escuela de Gobierno, Universidad Adolfo Ibáñez) 
Date:  2012–09 
URL:  http://d.repec.org/n?u=RePEc:uai:wpaper:wp_024&r=mic 
By:  Andrea Gallice (Department of Economics and Statistics (Dipartimento di Scienze EconomicoSociali e MatematicoStatistiche), University of Torino, Italy) 
Abstract:  A price reveal auction is a Dutch auction in which the current price of the item on sale remains hidden. Bidders can privately observe the price only by paying a fee, and every time a bidder does so, the price falls by a predetermined amount. We solve for the perfect Bayesian equilibria of the game. If the number of participants n is common knowledge, then in equilibrium at most one bidder observes the price and the profits that the mechanism raises, if any, are only marginally higher than those that would stem from a normal sale. If instead n is a random variable then multiple entry can occur and profitability is enhanced. 
Keywords:  payperbid auctions, endogenous price decrease 
JEL:  C72 D44 
Date:  2012–11 
URL:  http://d.repec.org/n?u=RePEc:tur:wpapnw:015&r=mic 
By:  Bettina Klose and Paul Schweinzer 
Abstract:  We develop the idea of using meanvariance preferences for the analysis of the firstprice, allpay auction. On the bidding side, we characterise the optimal strategy in symmetric allpay auctions under meanvariance preferences for general distributions of valuations and any number of bidders. We find that, in contrast to winnerpay auction formats, only hightype bidders increase their bids relative to the riskneutral case while low types minimise variance exposure by bidding low. Introducing asymmetric variance aversions across bidders into a Uniform valuations, twoplayer framework, we show that a more varianceaverse type bids always higher than her less varianceaverse counterpart. Taking meanvariance bidding behaviour as given, we show that an expected revenue maximising seller may want to optimally limit the number of participants. Although expected revenue for riskneutral bidders typically dominates revenue under meanvariance bidding, if the seller himself takes account of the variance of revenue, he may find it preferable to attract bidders endowed with meanvariance preferences. 
Keywords:  Auctions, Contests, MeanVariance preferences 
JEL:  C7 D7 D81 
Date:  2012–11 
URL:  http://d.repec.org/n?u=RePEc:yor:yorken:12/32&r=mic 
By:  Argenton, C. (Tilburg University); Prüfer, J. (Tilburg University) 
Date:  2012 
URL:  http://d.repec.org/n?u=RePEc:ner:tilbur:urn:nbn:nl:ui:125117898&r=mic 
By:  Juan M. Gallego 
Abstract:  This paper investigates the role of works councils in a simple agency framework in which works councils are supposed to monitor manager’s information on behalf of the workforce, but they are independent agents who might pursue their private interest. First, we consider that workers can incentivize works councils through contingent monetary payments. In order to deter collusion, workers must pay higher compensations in states of nature where they can be expropriated by potential coalitions among works councils and management. Collusion makes contingent payments costly and reduces workers’ payoffs. Second, when elections are the exclusive mechanisms to align works councils’ interest, only well compensated representatives would face an intertemporal tradeoff between accepting management’s transfers at first period and losing rents at the second period. Elections increase the cost of entering on collusive behavior with management and works councils will try to behave on the employees’ interest. 
Date:  2012–11–19 
URL:  http://d.repec.org/n?u=RePEc:col:000092:010092&r=mic 
By:  Volker Hahn (Department of Economics, University of Konstanz, Germany) 
Abstract:  What is the optimal size of expert committees? To address this question, I present a model of a committee of experts with career concerns. Each expert may observe an argument about the state of the world but be unsure about the argument's soundness. Experts may remain silent or compete for the opportunity to announce an argument. I show that experts become more reluctant to speak in larger committees. This effect is sufficiently strong to make small groups of experts optimal. At the same time, a small committee may be superior to an individual expert. 
Keywords:  experts, committees, career concerns, veriable information, information aggregation. 
JEL:  D71 D82 
Date:  2012–11–19 
URL:  http://d.repec.org/n?u=RePEc:knz:dpteco:1224&r=mic 
By:  Sunku Hahn (school of economics, Yonsei University) 
Abstract:  Many people are not free from past sunk costs in their decision making processes, even though economic theory tells them to forget the sunk costs. In this paper we will show that it can be a rational behavior for the people not to forget the sunk cost when people are concerned with their future reputations. 
Keywords:  sunk cost, reputation 
JEL:  D8 
Date:  2012–11–15 
URL:  http://d.repec.org/n?u=RePEc:yon:wpaper:2012rwp52&r=mic 
By:  JongHee Hahn (School of Economics, Yonsei University); JinHyuk Kim 
Abstract:  In network industries, we often observe frequent upgrades of existing products as well as delayed introductions of new products. In order to explain these contrasting phenomena, this paper examines a durablegood monopolist's incentive for R&D in vestment in new product development in a market with network effects. We show that if the network effect is strong the monopolist underinvests in R&D compared to the commitment level, whereas overinvestment occurs when the network effect is weak. The monopolist also chooses full intergenerational compatibility between products. We then extend the analysis to the cases of potential entry and successive innovations, and examine how the results change in these extensions. 
Keywords:  Planned Obsolescence, Network Effects, Vaporware 
JEL:  L12 L15 M21 
Date:  2012–10 
URL:  http://d.repec.org/n?u=RePEc:yon:wpaper:rwp201243&r=mic 
By:  Choi, Jay; Jeon, DohShin; Kim, ByungCheol 
Abstract:  We analyze competition between interconnected networks when content is heterogeneous in its sensitivity to delivery quality. In a twosided market framework, we characterize the equilibrium in a neutral network constrained to offer the same quality and assess the impact of such a constraint visàvis a nonneutral network where Internet service providers (ISPs) are allowed to engage in second degree price discrimination with a menu of qualityprice pairs. We find that the merit of net neutrality regulation depends crucially on content providers' business models. More generally, our analysis can be considered as a contribution to the literature on seconddegree price discrimination in twosided platform markets. 
Keywords:  Net neutrality, Internet interconnection, Twosided markets, Seconddegree price discrimination, Access (Termination) charges, CPs' business models 
JEL:  D4 L1 L5 
Date:  2012–11 
URL:  http://d.repec.org/n?u=RePEc:tse:wpaper:26550&r=mic 
By:  Normann, HansTheo; Rösch, Jürgen; Schultz, Luis Manuel 
Abstract:  We explore whether buyer groups, in which firms legally purchase inputs jointly, facilitate collusion in the product market. In a repeated game, abandoning the buyer group altogether or excluding single firms from them constitute more severe credible threats, hence, in theory buyer groups facilitate collusion. We run several experimental treatments in a threefirm Cournot framework to test these predictions, and we also explore the impact communication has on buyer groups. The experimental results show that buyer groups lead to lower outputs when groups can exclude single firms. Communication is identified as a main factor causing collusive product markets.  
Keywords:  buyer groups,cartels,collusion,communication,experiments,repeated games 
JEL:  C7 C9 L4 L41 
Date:  2012 
URL:  http://d.repec.org/n?u=RePEc:zbw:dicedp:74&r=mic 
By:  Peter A. Streufert (University of Western Ontario) 
Abstract:  We introduce three definitions. First, we let a "basement" be a set of nodes and actions that supports at least one assessment. Second, we derive from an arbitrary basement its implied "plausibility" (i.e. infiniterelativelikelihood) relation among the game's nodes. Third, we say that this plausibility relation is "additive" if it has a completion represented by the nodal sums of a mass function defined over the game's actions. This last construction is built upon Streufert (2012)'s result that nodes can be specified as sets of actions. Our central result is that a basement has additive plausibility if and only if it supports at least one consistent assessment. The result's proof parallels the early foundations of probability theory and requires only Farkas' Lemma. The result leads to related characterizations, to an easily tested necessary condition for consistency, and to the repair of a nontrivial gap in a proof of Kreps and Wilson (1982). 
Keywords:  plausibility relation;additive representation; plausibility mass function; infinite relative likelihood 
JEL:  C72 
Date:  2012 
URL:  http://d.repec.org/n?u=RePEc:uwo:uwowop:20123&r=mic 
By:  Chan, Raymond H.; Clark, Ephraim; Wong, WingKeung 
Abstract:  This paper studies some properties of stochastic dominance (SD) for riskaverse and riskseeking investors, especially for the third order SD (TSD). We call the former ascending stochastic dominance (ASD) and the latter descending stochastic dominance(DSD). We first discuss the basic property of ASD and DSD linking the ASD and DSD of the first three orders to expectedutility maximization for riskaverse and riskseeking investors. Thereafter, we prove that a hierarchy exists in both ASD and DSD relationships and that the higher orders of ASD and DSD cannot be replaced by the lower orders of ASD and DSD. Furthermore, we study conditions in which third order ASD preferences will be 'the opposite of' or 'the same as' their counterpart third order DSD preferences. In addition, we construct examples to illustrate all the properties developed in this paper. The theory developed in this paper provides investors with tools to identify first, second, and third order ASD and DSD prospects and thus they could make wiser choices on their investment decision. 
Keywords:  Third order stochastic dominance; ascending stochastic dominance; descending stochastic dominance; expectedutility maximization; risk averters; risk seekers 
JEL:  D81 G11 C02 
Date:  2012–11–16 
URL:  http://d.repec.org/n?u=RePEc:pra:mprapa:42676&r=mic 
By:  Takashi Kamihigashi (Research Institute for Economics & Business Administration (RIEB), Kobe University, Japan) 
Abstract:  We establish some elementary results on solutions to the Bellman equation without introducing any topological assumption. Under a small number of conditions, we show that the Bellman equation has a unique solution in a certain set, that this solution is the value function, and that the value function can be computed by value iteration with an appropriate initial condition. We also show that the value function can be computed by the same procedure under alternative conditions. We apply our results to two optimal growth models, one with a discontinuous production function, the other with "roughly increasing" returns. 
Keywords:  Dynamic programming, Bellman equation, Value function, Fixed point 
JEL:  C61 
Date:  2012–11 
URL:  http://d.repec.org/n?u=RePEc:kob:dpaper:dp201231&r=mic 
By:  Prüfer, J. (Tilburg University); Walz, U. 
Date:  2012 
URL:  http://d.repec.org/n?u=RePEc:ner:tilbur:urn:nbn:nl:ui:125117896&r=mic 