Collusion as public monitoring becomes noisy: Experimental evidence

This paper uses laboratory experiments to test the implications of the theory of repeated games on equilibrium payoffs and estimate strategies in an infinitely repeated prisoners' dilemma game with imperfect public monitoring. We find that subjects' payoffs (i) decrease as noise increases, and (ii) are lower than the theoretical maximum for low noise, but exceed it for high noise. Under the assumption that the subjects' strategy uses thresholds on the public signal for transition between cooperation and punishment states, we find that the best fitting strategy simply compares the most recent public signal against a single threshold.     

Rationale behind IPO Underpricing: Evidence from Asian REIT IPOs

This article examines the rationale behind IPO underpricing using a sample of REIT IPOs in Asia. Although the IPOs registered an average initial return of 3.08%, the issuers were able to sell the IPO shares above their fundamental values by timing the listings in periods when existing REIT stocks are traded at a premium to their net asset values (NAV). An IPO could therefore be underpriced and yet produce a net gain for the issuer. The issuers’ net gain from IPO is, however, negatively related to long‐run performance of REIT IPOs.     

Log Mean-Variance Portfolio Selection Under Regime Switching

In this paper we develop a portfolio selection theory under regime switching means and volatilities. We use log mean-variance as the portfolio selection criteria and, as a result, the theory is made substantially easier to implement than other existing theories. Moreover, the estimated regimes are easy to interpret as one of the regimes corresponds to the business cycle turning points. Finally, we conduct an asset allocation simulation and obtain reasonable results by introducing an idea of switching volatility targets.     

Evolution of Beliefs and the Nash Equilibrium of Normal Form Games

The paper formulates a simple two-person model of learning with pattern recognition and discusses its implications. In particular, it focuses on the asymptotic behavior of players' beliefs when the game has a mixed-strategy Nash equilibrium.Journal of Economics LiteratureClassification Numbers: C72, D83.     

SHORT SELLING AND MISPRICINGS WHEN FUNDAMENTALS ARE KNOWN: EVIDENCE FROM NYSE‐TRADED CLOSED‐END FUNDS

The larger a closed‐end fund's premium over its portfolio value, the more intensely it is sold short. This behavior should reduce mispricings. However, short selling affects neither the observed rate at which premia revert to fundamental values nor the rate of return on a fund's shares. This apparent contradiction can be explained as follows: short selling does reduce prices, but the effect is impounded into prices by the time short positions are tabulated by the NYSE each month. Consequently, the monthly short selling data do not predict future price movements.     

Honesty,Diligence and Skill: Risk Sharing and Specialization in the Kiryu Silk Weaving Cluster,Japan

Many economies have seen growth in industrial clusters during their industrialization, and the relational contracts between manufacturers and subcontractors are often the organizational basis of clusters. We predict that, if manufacturers form relational contracts with subcontractors, if manufacturers closely collude with each other when trading with subcontractors, if information about subcontractors’ past actions is only imperfectly shared by manufacturers as hearsay, and if demand shock is considerable, then premium subcontractors suffer more from market volatility than ordinary subcontractors would and hence, it is optimal for manufacturers to shield premium subcontractors against the risk. We then study Kiryu, a kimono weaving cluster that expanded from the late nineteenth century with the development of new synthetic dyeing techniques. We show that premium subcontracting weavers were allowed long‐term relational contracts and specialization, which shielded already honest weavers against market volatility and induced them to be diligent and to acquire skills.     

Collusion in Dynamic Bertrand Oligopoly with Correlated Private Signals and Communication

This paper studies collusion in repeated Bertrand oligopoly when stochastic demand levels for the product of each firm are their private information and are positively correlated. It derives general sufficient conditions for efficient collusion through communication and a simple grim-trigger strategy. This analysis is then applied to a model where the demand signal has multiple random components which respond differently to price deviations. In this model, it is shown that the above sufficient conditions hold if idiosyncratic noise terms are sufficiently small. Journal of Economic Literature Classification Numbers: C72, D82.     

A consumer-based model of competitive diffusion: the multiplicative effects of global and local network externalities

Competitive diffusion of two incompatible technologies, such as PC vs. Macintosh, VHS vs. Betamax and so on, is studied under the framework of a spatial game in which consumers are distributed on a two-dimensional square lattice network. The consumers play coordination-like games with their nearest neighbors and imitate the most successful strategy in their neighborhood in terms of aggregated payoffs after each round. The effects of global network externality are realized in the dynamic payoff matrix of the game, and the framework of spatial game provides the model with the effects of local network externality. These two types of externalities are set as multiplicative, that is, as nonlinear. Both simulations and mean-field approximation show that not only total but also partial standardization (robust polymorphic equilibrium) occurs depending upon the parameters and initial configurations, even when there are positive effects of both global and local network externalities. Moreover, effects of innovation factors that alter paths toward a lock-in situation are studied. It is shown that both the timing and the size of the innovation factors matter for a disadvantaged technology in order to overwhelm a market.JEL Classification: C7, D8, O3We are obliged to Professor John Paul Boyd at the University of California, Irvine and our anonymous referees for their constructive comments.     

Collusion through mediated communication in repeated games with imperfect private monitoring

Summary. This paper studies repeated games with imperfect private monitoring when there exists a third-party mediator who coordinates play by giving non-binding instructions to players on which action to take and by collecting their private information. The paper presents a Nash-threat folk theorem for a communication equilibrium based on such mediation when monitoring is jointly -perfect in the sense that every player is almost perfectly monitored collectively by other players.JEL Classification Numbers: C72, D82.I am very grateful to Mark Armstrong, V. Bhaskar, and Michihiro Kandori for helpful comments. Part of this research was conducted while I was visiting the University College London. Their hospitality is gratefully acknowledged.