Juan Ortner

Direct Implementation with Minimally Honest Individuals

I consider a standard implementation problem under complete information when agents have a minimal degree of honesty. In particular, I assume that agents are white lie averse: they strictly prefer to tell the truth whenever lying has no effect on their material payoff. I show that if there are at least five agents who are all white lie averse and if I impose either of two refinements of Nash equilibrium, then a simple direct mechanism fully implements any social choice function.

Durable goods monopoly with stochastic costs

I study the problem of a durable goods monopolist who lacks commitment power and whose marginal cost of production varies stochastically over time. I show that a monopolist with stochastic costs usually serves the different types of consumers at different times and charges them different prices. When the distribution of consumer valuations is discrete, the monopolist exercises market power and there is inefficient delay. When there is a continuum of types, the monopolist cannot extract rents and the market outcome is efficient.

Optimism, Delay and (In)Efficiency in a Stochastic Model of Bargaining

I study a bilateral bargaining game in which the size of the surplus follows a stochastic process and in which players might be optimistic about their bargaining power. Following Yildiz (2003), I model optimism by assuming that players have different beliefs about the recognition process. I show that the unique subgame perfect equilibrium of this game might involve inefficient delays. I also show that these inefficiencies disappear when players can make offers arbitrarily frequently.

Delays and Partial Agreements in Multi-Issue Bargaining

We model a situation in which two players bargain over two issues (pies), one of which can only be resolved at a future date. We find that if the players value the issues asymmetrically (one player considers the existing issue more important than the future one, while the other player has the opposite valuation) then they may delay agreement on the first issue until the second one is finally on the table. If we allow for partial agreements, then the players never leave an issue completely unresolved. They either make a partial agreement on the first issue, and wait for the second one to emerge before completing the agreement; or they come to complete agreements on each of the issues at their earliest possible dates. We discuss applications to legislative bargaining and international trade negotiations.

Making Corruption Harder: Asymmetric Information, Collusion, and Crime

We model criminal investigation as a principal-agent-monitor problem in which the agent can bribe the monitor to destroy evidence. Building on insights from Laffont and Martimort’s 1997 paper, we study whether the principal can profitably introduce asymmetric information between agent and monitor by randomizing the monitor’s incentives. We show that it can be the case, but the optimality of random incentives depends on unobserved preexisting patterns of private information. We provide a data-driven framework for policy evaluation requiring only unverified reports. A potential local policy change is an improvement if, everything else equal, it is associated with greater reports of crime.

Collusion in Auctions with Constrained Bids: Theory and Evidence from Public Procurement

We study the mechanics of cartel enforcement and its interaction with bidding constraints in the context of repeated procurement auctions. Under collusion, bidding constraints weaken cartels by limiting the scope for punishment. This yields a test of collusive behavior exploiting the counter-intuitive prediction that introducing minimum prices can lower the distribution of winning bids. The models predictions are borne out in procurement data from Japan, where we find considerable evidence that collusion is weakened by the introduction of minimum prices.