Independent Random Matching

Random matching models with a continuum population are widely used in economics to study environments where agents interact in small coalitions. This paper provides foundations to such models. In particular, the paper establishes an existence result for random matchings that are universal in the sense that certain desirable properties are satisfied for any assignment of types to agents. The result applies to infinitely many types of agents, thus covering random matching models which are currently used in the literature without a foundation. Furthermore, the paper provides conditions guaranteeing uniqueness of random matching.Random matching; Involution; Independence; Continuum population; Fubini extension

Tie-Breaking Rules and Divisibility in Experimental Duopoly Markets

This experimental study investigates pricing behavior of sellers in duopoly markets with posted prices and market power. The two treatment variables are given by tie breaking rules and divisibility of the price space. The first treatment variable deals with the rule under which demanded units are allocated between sellers in case of a price tie. A change in divisibility is modeled by making the sellers' price space finer or coarser. The main finding is that the incidence of perfect collusion is significantly higher under the sharing tie breaking rule than under the random (coin-toss) one, especially when the price space is less divisible.Collusion, Tie Breaking Rules, Divisibility, Bertrand model

Tie-Breaking Rules and Divisibility in Experimental Duopoly Markets

We investigate pricing behavior of sellers in duopoly markets with posted prices and market power. The two treatment variables are given by tie-breaking rules and divisibility of the price space. The first treatment variable deals with the rule under which demanded units are allocated between sellers in case of a price tie. A change in divisibility is modeled by making the sellers’ price space finer or coarser. We find that the incidence of perfect collusion is significantly higher under the sharing tie-breaking rule than under the random (coin-toss) one, especially when the price space is less divisible.Collusion; Tie-breaking rules; Divisibility; Bertrand model

An Experimental Study of Bubble Formation in Asset Markets Using the Tâtonnement Trading Institution

We report the results of an experiment designed to study the role of institutional structure in the formation of bubbles and crashes in laboratory asset markets. In a setting employing double auctions and call markets as trading institutions, bubbles and crashes are a quite robust phenomenon. The only factor appearing to reduce bubbles is experience across markets. In this study, we employ the tâtonnement trading institution, which has not been previously explored in laboratory asset markets, despite its historical and contemporary relevance. The results show that bubbles are significantly reduced, suggesting that the trading institution plays a crucial role in the formation of bubbles.Experimental Asset Markets; Price Bubbles; Trading Institutions; Tâtonnement

Stationarity without Degeneracy in a Model of Commodity Money

We develop a model of macroeconomic heterogeneity inspired by the Kiyotaki-Wright (1989) formulation of commodity money, with the addition of linear utility and idiosyncratic shocks to savings. We consider two environments. In the benchmark case, the consumer in a meeting is chosen randomly. In the auctions case, the individual holding more money can be selected to be the consumer. We show that in both environments socially optimal trading decisions (that are individually acceptable) are stationary and solve a tractable static op- timization problem. Savings decisions in the benchmark case are re- markably invariant to mean-preserving changes in the distribution of shocks. This result is overturned in the auctions case.Macroeconomics with heterogeneous savings; commodity money with linear adjustments; mechanism design; auctions

Random Matching and Aggregate Uncertainty

Random matching is often used in economic models as a means of introducing uncertainty in sequential decision problems. We show that random matching schemes that satisfy standard conditions on proportionality are not unique. Two examples show that in a simple growth model, radically di¤erent optimal behavior can result from distinct matching schemes satisfying identical proportionality conditions. That is, non-uniqueness has interesting economic implications since it a¤ects the reward and the transi- tion structures. We propose information entropy as a natural method for selecting unique matching structures for these models. Next, we give conditions on the reward and transition structures of sequential decision models under which the models are not a¤ected by non-uniqueness of the matching scheme.

Random Matching and Aggregate Uncertainty

Random matching is often used in economic models as a means of introducing uncertainty in sequential decision problems. We show that random matching schemes that satisfy standard conditions on proportionality are not unique. Two examples show that in a simple growth model, radically di¤erent optimal behavior can result from distinct matching schemes satisfying identical proportionality conditions. That is, non-uniqueness has interesting economic implications since it a¤ects the reward and the transi- tion structures. We propose information entropy as a natural method for selecting unique matching structures for these models. Next, we give conditions on the reward and transition structures of sequential decision models under which the models are not a¤ected by non-uniqueness of the matching scheme

Independent Random Matching

Random matching models with a continuum population are widely used in economics to study environments where agents interact in small coalitions. This paper provides foundations to such models. In particular, the paper establishes an existence result for random matchings that are universal in the sense that certain desirable properties are satisfied for any assignment of types to agents. The result applies to infinitely many types of agents, thus covering random matching models which are currently used in the literature without a foundation. Furthermore, the paper provides conditions guaranteeing uniqueness of random matching

An experimental investigation of overdissipation in the all pay auction

Pervasive overbidding represents a well-documented feature of all-pay auctions. Aggregate bids exceed Nash predictions in laboratory experiments, and individuals often submit bids that guarantee negative profits. This paper examines three factors that may reduce pervasive overbidding: (a) repetition (experience), (b) reputation (strangers vs. partners) and (c) active participation. We find that aggregate over-dissipation diminishes but is not eliminated with repetition, and that repetition, in conjunction with active participation generates bids consistent with the static Nash predictions