Optimal bilateral trade of multiple objects

We study a private-values buyer–seller problem with multiple objects. Valuations are binary and i.i.d. We construct mechanisms that span the set of all Pareto-efficient outcomes. The induced trading rules for objects are linked in a simple way.     

Optimal private good allocation: The case for a balanced budget

In an independent private value auction environment, we are interested in strategy-proof mechanisms that maximize the agents' residual surplus, that is, the utility derived from the physical allocation minus transfers accruing to an external entity. We find that, under the assumption of an increasing hazard rate of type distributions, an optimal deterministic mechanism never extracts any net payments from the agents, that is, it will be budget-balanced. Specifically, optimal mechanisms have a simple “posted price” or “option” form. In the bilateral trade environment, we obtain optimality of posted price mechanisms without any assumption on type distributions.     

A generalized design for bilateral trade flow models

This paper suggests a full interaction effects design to analyze bilateral trade flows. This is illustrated with an unbalanced panel of bilateral trade between the triad (EU15, USA and Japan) economies and their 57 most important trading partners over the period 1986–1997. Our full interaction model finds empirical support for the New Trade Theory and Linder’s hypothesis. We show that the omission of one or more interaction effects can result in biased estimates and misleading inference.     

Motivation for bilateral aid allocation: Altruism or trade benefits

This paper argues that OECD countries allocate more aid to recipient nations who import goods in which donor nations have a comparative advantage in production. The estimates indicate that a substantially larger amount of aid is provided to recipients who import capital goods, while imports by other category groups have no significant effects. Given that developed donor nations are major producers and exporters of capital goods, this result at least partially supports their trade benefits motive. Donors also appear to be more concerned about alleviating physical miseries (infant mortality) and rewarding good human rights conditions, but less towards reducing economic hardships (poverty). Moreover, the usual political and strategic considerations of donors continue to be the major determinants of aid allocation even in the Post Cold War era.     

On the optimality of privacy in sequential contracting

This paper studies the exchange of information between two principals who contract sequentially with the same agent, as in the case of a buyer who purchases from multiple sellers. We show that when (a) the upstream principal is not personally interested in the downstream level of trade, (b) the agent's valuations are positively correlated, and (c) preferences in the downstream relationship are separable, then it is optimal for the upstream principal to offer the agent full privacy. On the contrary, when any of these conditions is violated, there exist preferences for which disclosure is strictly optimal, even if the downstream principal does not pay for the information. We also examine the effects of disclosure on welfare and show that it does not necessarily reduce the agent's surplus in the two relationships and in some cases may even yield a Pareto improvement.     

Computationally-feasible truthful auctions for convex bundles

In many economic settings, like spectrum and real-estate auctions, geometric figures on the plane are for sale. Each bidder bids for his desired figure, and the auctioneer has to choose a set of disjoint figures that maximizes the social welfare. In this work, we design mechanisms that are both incentive compatible and computationally feasible for these environments. Since the underlying algorithmic problem is computationally hard, these mechanisms cannot always achieve the optimal welfare; Nevertheless, they do guarantee a fraction of the optimal solution. We differentiate between two information models—when both the desired figures and their values are unknown to the auctioneer or when only the agents' values are private data. We guarantee different fractions of the optimal welfare for each information model and for different families of figures (e.g., arbitrary convex figures or axis-aligned rectangles). We suggest using a measure on the geometric diversity of the figures for expressing the quality of the approximations that our mechanisms provide.     

How to talk to multiple audiences

Stochastic fictitious play (SFP) assumes that agents do not try to influence the future play of their current opponents, an assumption that is justified by appeal to a setting with a large population of players who are randomly matched to play the game. However, the dynamics of SFP have only been analyzed in models where all agents in a player role have the same beliefs. We analyze the dynamics of SFP in settings where there is a population of agents who observe only outcomes in their own matches and thus have heterogeneous beliefs. We provide conditions that ensure that the system converges to a state with homogeneous beliefs, and that its asymptotic behavior is the same as with a single representative agent in each player role.     

Market and non-market mechanisms for the optimal allocation of scarce resources

A number of identical objects is allocated to a set of privately informed agents. Agents have linear utility in money. The designer wants to assign objects to agents that possess specific traits, but the allocation can only be conditioned on the willingness to pay and on observable characteristics. I solve for the optimal mechanism. The choice between market or non-market mechanisms depends on the statistical linkage between characteristics valued by the designer and willingness to pay.     

Incentives for budget discipline in the presence of elections

This paper presents a mechanism to mitigate the adverse consequences of the political budget cycle on social welfare. We use a simplified two-period version of Rogoff's [Rogoff, K., 1990. Equilibrium political budget cycles. American Economic Review 80, 21–36.] rational budget cycle model to address the normative issue of reducing the budget deficit in pre-electoral periods. A regulation consisting of a sanction scheme contingent on fiscal policy joint with a fixed transfer is shown to provide the appropriate incentives for budget discipline in the presence of elections.     

Auctions for social lending: A theoretical analysis

Prosper, today the second largest social lending marketplace with nearly 1.5 million members and $380 million in funded loans, employed an auction mechanism amongst lenders to finance each borrower's loan until 2010. Given that a basic premise of social lending is cheap loans for borrowers, how does the Prosper auction do in terms of the borrower's payment, when lenders are strategic agents with private true interest rates? We first analyze the Prosper auction as a game of complete information and fully characterize its Nash equilibria, and show that the uniform-price Prosper mechanism, while simple, can lead to much larger payments for the borrower than the VCG mechanism. We next compare the Prosper mechanism against the borrower-optimal auction in an incomplete information setting, and conclude by examining the Prosper mechanism when modeled as a dynamic auction, and provide tight bounds on the price for a general class of bidding strategies.     

The value of information for auctioneers

An auctioneer wants to sell an indivisible object to one of multiple bidders, who have private information about their valuations of the object. A bidder's information structure determines the accuracy with which the bidder knows her private valuation. The main result of the paper is that the auctioneer's revenue is a convex function of bidders' information structures. One implication is that assigning asymmetric information structures instead of symmetric information structures to bidders is always revenue-enhancing. This paper generalizes a result of Bergemann and Pesendorfer [D. Bergemann, M. Pesendorfer, Information structures in optimal auctions, J. Econ. Theory 137 (2007) 580–609], who show that revenue-maximizing information structures are asymmetric.     

Truthful approximation mechanisms for restricted combinatorial auctions

When attempting to design a truthful mechanism for a computationally hard problem such as combinatorial auctions, one is faced with the problem that most efficiently computable heuristics can not be embedded in any truthful mechanism (e.g. VCG-like payment rules will not ensure truthfulness).We develop a set of techniques that allow constructing efficiently computable truthful mechanisms for combinatorial auctions in the special case where each bidder desires a specific known subset of items and only the valuation is unknown by the mechanism (the single parameter case). For this case we extend the work of Lehmann, O'Callaghan, and Shoham, who presented greedy heuristics. We show how to use If-Then-Else constructs, perform a partial search, and use the LP relaxation. We apply these techniques for several canonical types of combinatorial auctions, obtaining truthful mechanisms with provable approximation ratios.     

License auctions with royalty contracts for (winners and) losers

This paper revisits the licensing of a non-drastic process innovation by an outside innovator to a Cournot oligopoly. We propose a new mechanism that combines a restrictive license auction with royalty licensing. This mechanism is more profitable than standard license auctions, auctioning royalty contracts, fixed-fee licensing, pure royalty licensing, and two-part tariffs. The key features are that royalty contracts are auctioned and that losers of the auction are granted the option to sign a royalty contract. Remarkably, combining royalties for winners and losers of the auction makes the integer constraint concerning the number of licenses irrelevant.     

Mechanisms for a spatially distributed market

We consider the problem of a spatially distributed market with strategic agents. A single good is traded in a set of independent markets, where shipment between markets is possible but costly. The problem has previously been studied in the non-strategic case, in which it can be analyzed and solved as a min-cost-flow problem. We consider the case where buyers and sellers are strategic. Our first result gives a double characterization of the VCG prices, first as distances in a certain residue graph and second as the minimal (for buyers) and maximal (for sellers) equilibrium prices. This provides a computationally efficient, individually rational and incentive compatible welfare maximizing mechanism. This mechanism is, necessarily, not budget balanced and we also provide a budget-balanced mechanism (which is also computationally efficient, incentive compatible and individually rational) that achieves high welfare. Finally, we present results for some extensions of the model.