Dynamic Equilibrium Bunching

In this paper, we analyze the asymmetric pure strategy equilibria in a dynamic game of pure information externality. Each player receives a private signal and chooses whether and when to invest. In some of the periods, only a subgroup of the players make decisions, which we call bunching, while the rest of the players do not invest regardless of their signals. Bunching is different from herding; it occurs in the first period and recursively until herding takes place or the game runs out of undecided players. We find that any asymmetric pure strategy equilibrium is more efficient than the symmetric mixed strategy equilibrium. When players become patient enough, herding of investment disappears in the most efficient asymmetric pure strategy equilibrium, while the least efficient asymmetric pure strategy equilibrium resembles those in a fixed timing model, producing an exact match when the discount factor is equal to 1. Bunch sizes are shown to be independent of the total number of players; adding more players to the game need not change early players' behavior. All these are unique properties of the asymmetric pure strategy equilibria. We also show that the asymmetric pure strategy equilibria can accommodate small heterogeneities of the players in costs of acquiring signals, discount factors, or degree of risk aversion. In any of these environments, there exists a unique welfare maximizing equilibrium which provides a natural way for the players to coordinate.bunching, herding, endogenous timing, asymmetric equilibrium, information externality

Deterministic versus Stochastic Mechanisms in Principal–Agent Models

This paper shows that, contrary to what is generally believed, decreasing concavity of the agent’s utility function with respect to the screening variable is not sufficient to ensure that stochastic mechanisms are suboptimal. The paper demonstrates, however, that they are suboptimal whenever the optimal deterministic mechanism exhibits no bunching. This is the case for most applications of the theory and therefore validates the literature’s usual focus on deterministic mechanisms

Deterministic versus Stochastic Mechanisms in Principal–Agent Models

This paper shows that, contrary to what is generally believed, decreasing concavity of the agent’s utility function with respect to the screening variable is not sufficient to ensure that stochastic mechanisms are suboptimal. The paper demonstrates, however, that they are suboptimal whenever the optimal deterministic mechanism exhibits no bunching. This is the case for most applications of the theory and therefore validates the literature’s usual focus on deterministic mechanisms.principal-agent theory; mechanism design; deterministic mechanisms; randomization; bunching.

Green Payments and Dual Policy Goals

We use a mechanism design framework to analyze the optimal design of green payment policies with the dual goals of conservation and income support for small farms. Each farm is characterized by two dimensions of attributes: farms size and conservation efficiency. The policymaker may not be able to use the attributes as an explicit criterion for payments. We characterize optimal policy when conservation efficiency is unobservable to policy-makers, and when farm size is also unobservable. An income support goal is shown to reduce the conservation distortion caused by asymmetric information. The cost of optimal green payment mechanisms is shown to depend crucially on whether large or small farms have greater conservation efficiency.

Rigidity in bilateral trade with holdup

This paper studies bilateral trade in which the seller makes a hidden investment that influences the buyer's hidden valuation. In general it is impossible to implement both first-best efficient trade and efficient investment using budget-balanced trading mechanisms. The paper fully characterizes the constrained efficient contracts. It is shown that the optimal tradeoff between allocative efficiency and incentive provision results in rigidity in trade, the degree of which depends on the seriousness of the holdup problem. Sufficient conditions are also provided for full separation of buyer types to take place in optimal contracts when the holdup problem is not too severe. The seller may overinvest relative to the first best.Bilateral contracting, hidden action and hidden information, holdup problem, nonlinear pricing

Optimal Trading Mechanisms with Ex Ante Unidentified Traders

We analyze optimal trading mechanisms in an exchange economy where each trader owns some units of a good to be traded and may be either a seller or a buyer, depending on the realization of the privately observed valuations. The concept of virtual valuation is extended to ex ante unidentified traders; contrary to the case where each trader is assigned a role as either a buyer or a seller, the traders' virtual valuations now depend on the choice of the trading mechanism and are generally non-monotonic even if the distribution of valuations is regular. We show that the trading mechanisms that maximize a broker's expected profit or expected total gains from trade are generalized double auctions which maximize the gains from trade measured in some modified monotonic virtual valuations for the traders. The bunching phenomena, which are here specific to ex ante unidentified traders, will be a general feature in these mechanisms. Furthermore, the randomization rule by which ties are broken is now part of the design of the optimal mechanisms. Finally, we show that the optimal mechanism converges toward a simple bid-ask mechanism as the number of participants in the market increases.

Monitoring Subcontracting in a Suppliers' Hierarchy

In this paper we study the delegation of a production process in a three-tier hierarchy. The principal contracts directly only with the supplier that produces the ?rst input leaving him in charge of the contract for the production of the second input. We allow the principal to costlessly monitor the communication between the agents at the subcontracting stage in an attempt to save on informa- tional rents and improve productive e¢ ciency. We show that, if the contractor is free to choose the type of subcontract, he must be given additional incen- tives to acquire information about the subcontractor which will then be object of the monitoring. The monitoring is therefore much less e¤ective then when the principal can force the contractor into choosing her preferred subcontract.Adverse Selection, Hierarchies, Delegation, Monitoring.