Comment on “Correlated information, mechanism design and informational rents” [J. Econ. Theory 123 (2) (2005) 210–217]

We amend an error in [S. Parreiras, Correlated information, mechanism design and informational rents, J. Econ. Theory 123 (2005) 210–217]. Consequently, it is in general not possible to reinterpret a mechanism design model that violates the spanning condition of Crémer and McLean [J. Crémer, R. McLean, Full extraction of the surplus in bayesian, dominant strategy auctions, Econometrica 56 (1988) 1247–1258] as one in which agents hold private information about the informativeness of their signals about other agents? types. Instead, such an interpretation is warranted only when the weights used to span an agent?s set of beliefs stand in a singular relation with the prior type distribution that is known as an alternative characterization of Blackwell dominance.     

A comment on “School choice: An experimental study” [J. Econ. Theory 127 (1) (2006) 202-231]

We show that one of the main results in Chen and Sönmez (2006, 2008) [6] and [7] does no longer hold when the number of recombinations is sufficiently increased to obtain reliable conclusions. No school choice mechanism is significantly superior in terms of efficiency.     

Corrigendum to “School choice: An experimental study” [J. Econ. Theory 127 (1) (2006) 202-231]

We correct an inconsistency in the efficiency comparison reported in [Y. Chen, T. Sönmez, School choice: An experimental study, J. Econ. Theory 127 (1) (2006) 202-231]. The efficiency comparison of the three school choice mechanisms in our paper is based on recombinant estimation with an identical set of 10 tie-breakers, while the statistics reported in Table 7 is computed using 14,400 tie-breakers.     

Local equilibrium equivalence in probabilistic voting models

Electoral equilibria depend upon candidates' motivations. Maximization of expected vote share may not lead to the same behavior as maximization of the probability of winning the election. Accordingly, it is desirable to understand when electoral equilibria are insensitive to the choice of candidate motivations. This paper examines sufficient conditions for local equilibrium equivalence between expected vote share maximization and maximization of probability of victory in the spatial model of elections with probabilistic voters.     

Corrigendum to “Reserve price signaling” [J. Econ. Theory 135 (1) (2007) 253-268]

We find an error in [H. Cai, J. Riley, L. Ye, Reserve price signaling, J. Econ. Theory 135 (1) (2007) 253-268]. The existence of the separating signaling equilibrium is not challenged, but the related comparative statics, while valid in the case without informational externalities between bidders, do not generalize to the case with informational externalities as claimed by the authors. General results on the influence of the number of bidders are obtained in a linear specification of the informational externalities.     

Coalitional bargaining games with random proposers: Theory and application

We consider a non-cooperative coalitional bargaining game with random proposers in a general situation for which players differ in recognition probability and time preference. We characterize an efficient equilibrium as the generalized Nash bargaining solution that belongs to the core. The model is applied to wage bargaining between an employer and multiple workers. Although involuntary unemployment may occur in equilibrium, full employment emerges as players become sufficiently patient.     

A Blotto game with multi-dimensional incomplete information

We examine a multi-dimensional incomplete information Colonel Blotto game in which each player’s n-tuple of battlefield valuations is drawn from a common n-variate joint distribution function that is uniform on the non-negative orthant of the surface of a sphere.     

Strategic network formation through peering and service agreements

We introduce a game theoretic model of network formation in an effort to understand the complex system of business relationships between various Internet entities (e.g., Autonomous Systems, enterprise networks, residential customers). In our model we are given a network topology of nodes and links where the nodes act as the players of the game, and links represent potential contracts. Nodes wish to satisfy their demands, which earn potential revenues, but may have to pay their neighbors for links incident to them. We incorporate some of the qualities of Internet business relationships, including customer–provider and peering contracts. We show that every Nash equilibrium can be represented by a circulation flow of utility with certain constraints. This allows us to prove bounds on the prices of anarchy and stability. We also focus on the quality of equilibria achievable through centralized incentives.     

Rents, military elites, and political democracy

In autocratic regimes the military elite is in a position to extract rents, because without the support of the military the government is in general not able to sustain itself. In this paper, we empirically confirm the negative relation between transfers to the military and the degree of democracy for developing countries. We use an instrumental variable approach to account for the simultaneity that arises since the degree of democracy is itself a function of transfers to the military.     

“Burden sharing” in sovereign debt reduction

We examine a concerted debt reduction deal between a sovereign debtor, a private creditor, and an official creditor, who insures the deposits of the commercial bank. Our results show that a weakening of the financial position of the commercial bank reduces the contribution of the commercial bank and increases that of the official creditor, without affecting the net terms faced by the debtor. This result is robust to changes in seniority. Moreover, leaving both creditor values unchanged requires that commercial banks retire debt at “unfairly” high prices, while official creditors make a net contribution.     

Non-cooperative solutions for estate division problems

In an estate division problem an estate has to be divided among several players whose total entitlement to the estate exceeds its size. This paper extends the non-cooperative approach through a claim game, as initiated by O?Neill (1982), by allowing players to put multiple claims on the same part of the estate, and by considering the case where individual entitlements may exceed the estate. A full characterization of the set of Nash equilibria of the claim game is obtained both for restricted estate division problems, where individual entitlements do not exceed the estate, and for the general case. Variations on the claim game are considered, which result in proportional division in equilibrium.     

Admissibility and common belief

The concept of ‘fully permissible sets’ is defined by an algorithm that eliminates strategy subsets. It is characterized as choice sets when there is common certain belief of the event that each player prefer one strategy to another if and only if the former weakly dominates the latter on the set of all opponent strategies or on the union of the choice sets that are deemed possible for the opponent. The concept refines the Dekel–Fudenberg procedure and captures aspects of forward induction.     

Voting blocs, party discipline and party formation

I study the strategic incentives to coordinate votes in an assembly. Coalitions form voting blocs, acting as single players and affecting the policy outcome. In an assembly with two exogenous parties I show how the incentives to accept party discipline depend on the types of the agents, the sizes of the parties, and the rules the blocs use to aggregate preferences. In a game of fully endogenous party formation, I find sufficient conditions for the existence of equilibria with one bloc, two blocs, and multiple blocs.     

A comment on “Egalitarianism and efficiency in repeated symmetric games” by V. Bhaskar [Games Econ. Behav. 32 (2000) 247-262]

We identify an error in Bhaskar?s (2000) Proposition 4. We provide counterexamples to this result and demonstrate that it is not correctable.     

On the folk theorem with one-dimensional payoffs and different discount factors

Proving the folk theorem in a game with three or more players usually requires imposing restrictions on the dimensionality of the stage-game payoffs. Fudenberg and Maskin (1986) assume full dimensionality of payoffs, while Abreu et al. (1994) assume the weaker NEU condition (“nonequivalent utilities”). In this note, we consider a class of n-player games where each player receives the same stage-game payoff, either zero or one. The stage-game payoffs therefore constitute a one-dimensional set, violating NEU. We show that if all players have different discount factors, then for discount factors sufficiently close to one, any strictly individually rational payoff profile can be obtained as the outcome of a subgame-perfect equilibrium with public correlation.     

Inequality and network structure

We explore the manner in which the structure of a social network constrains the level of inequality that can be sustained among its members, based on the following considerations: (i) any distribution of value must be stable with respect to coalitional deviations, and (ii) the network structure itself determines the coalitions that may form. We show that if players can jointly deviate only if they form a clique in the network, then the degree of inequality that can be sustained depends on the cardinality of the maximum independent set. For bipartite networks, the size of the maximum independent set fully characterizes the degree of inequality that can be sustained. This result extends partially to general networks and to the case in which a group of players can deviate jointly if they are all sufficiently close to each other in the network.     

Belief-free equilibria in games with incomplete information: Characterization and existence

We generalize the results of Hörner and Lovo (2009) [15] to N-player games with arbitrary information structure. First, we characterize the set of belief-free equilibrium payoffs under low discounting as the set of feasible payoffs that are individually rational, jointly rational, and incentive compatible. Second, we provide necessary and sufficient conditions on the information structure for this set to be non-empty.     

Mean absolute percentage error and bias in economic forecasting

This article develops a simple theoretical framework to show how forecasters may bias downward point predictions under the assumption that the asymmetric loss function is directly related to the (Mean) Absolute Percentage Error (M)APE.     

Aggregate information cascades

We introduce a new model of aggregate information cascades where only one of two possible actions is observable to others. Agents make a binary decision in sequence. The order is random and agents are not aware of their own position in the sequence. When called upon, they are only informed about the total number of others who have chosen the observable action before them. This informational structure arises naturally in many applications. Our most important result is that only one type of cascade arises in equilibrium, the aggregate cascade on the observable action. A cascade on the unobservable action never arises.