Two-sided matching with interdependent values

We introduce and study two-sided matching with incomplete information and interdependent valuations on one side of the market. An example of such a setting is a matching market between colleges and students in which colleges receive partially informative signals about students. Stability in such markets depends on the amount of information about matchings available to colleges. When colleges observe the entire matching, a stable matching mechanism does not generally exist. When colleges observe only their own matches, a stable mechanism exists if students have identical preferences over colleges, but may not exist if students have different preferences.     

Mechanism design with multidimensional, continuous types and interdependent valuations

We consider the mechanism design problem when agents’ types are multidimensional and continuous, and their valuations are interdependent. If there are at least three agents whose types satisfy a weak correlation condition, then for any decision rule and any ?>0 there exist balanced transfers that render truthful revelation a Bayesian ?-equilibrium. A slightly stronger correlation condition ensures that there exist balanced transfers that induce a Bayesian Nash equilibrium in which agents’ strategies are nearly truthful.     

Strategy-proof assignment on the full preference domain

We consider the problem of efficiently allocating several indivisible objects between agents who are to receive at most one object and whose preferences are private information. We examine this standard “assignment” problem from the perspective of mechanism design giving up the usual assumption of linear preferences and instead using a full preference domain (with indifferences permitted). We characterize two classes of mechanisms: (i) Bi-polar Serially Dictatorial Rules by Essential Single-Valuedness, Pareto Indifference, Strategy-Proofness and Non-Bossiness; and (ii) all selections from Bi-polar Serially Dictatorial Rules by Single-Valuedness, Efficiency, Strategy-Proofness and Weak Non-Bossiness. We compare the outcomes from the (Bi-polar) Serially Dictatorial Rules with the outcomes obtained using a market based approach, namely the “core” of the market. We show that all strongly efficient outcomes in the core can be generated using Serially Dictatorial Rules. Moreover, we argue that Serially Dictatorial Rules have an advantage over the market based approach in that they yield strongly efficient solutions for all preference profiles, making it possible to use randomization to restore equity. When preferences are private information, this type of ex ante equity cannot be implemented using the market based approach.     

Adverse selection problems without the Spence-Mirrlees condition

This paper studies a class of one-dimensional screening problems where the agent's utility function does not satisfy the Spence-Mirrlees condition (SMC). The strength of the SMC for hidden information problems is to provide a full characterization of implementable contracts using only the local incentive compatibility (IC) constraints. These constraints are equivalent to the monotonicity of the decision variable with respect to the agent's unobservable one-dimensional parameter. When the SMC is violated the local IC constraints are no longer sufficient for implementability and additional (global) IC constraints have to be taken into account. In particular, implementable decisions may not be monotonic and discretely pooled types must have the same marginal utility of the decision (or equivalently, get the same marginal tariff). Moreover, at the optimal decision, the principal must preserve the same trade-off between rent extraction and allocative distortion measured in the agent's marginal rent unit. In a specific setting where non-monotone contracts may be optimal we fully characterize the solution.     

Formula apportionment vs. separate accounting: A private information perspective

In 2002, the European Commission recommended that member countries use formula apportionment procedures to tax multinational companies. This departure from the standard separate accounting (transfer pricing) approach is an attempt to reduce the costs and distortions associated with auditing transfer prices. Unfortunately, apportionment formulas create their own economic distortions and, contrary to popular belief, they do not eliminate distortions due to asymmetric information between the multinational and the national tax authorities. In this paper, I explicitly model the role of private information in two tax competition games: one in which tax liabilities are calculated under formula apportionment and one in which tax liabilities are calculated under separate accounting and transfer prices are audited. Switching to a formula apportionment system affects the after-tax profit of multinationals and the tax revenues paid by both domestic and foreign firms. The direction and magnitude of the changes depend on the accuracy of the auditing technology and non-monotonically on multinational costs. The switch will have different effects on the tax receipts from domestic and foreign firms.     

The relevance of private information in mechanism design

Recent results in mechanism design show that as long as agents have correlated private information and are sufficiently risk neutral, it is possible to design mechanisms that leave agents with arbitrarily small information rents. We show that these full-rent-extraction results hinge on the implicit assumption that the agents’ beliefs uniquely determine their preferences. We present an example of the voluntary provision of a public good in which this assumption is relaxed, and consequently, even in highly correlated environments, if agents’ beliefs do not uniquely determine their preferences, then the extraction of the agents’ entire information rents is impossible.     

α‐SERIAL MECHANISMS FOR THE PROVISION OF AN EXCLUDABLE PUBLIC GOOD

We present a new class of “α‐serial mechanisms” for the provision of an excludable public good. Those mechanisms have a similar structure to the serial mechanism, but may let the non‐consumers pay a positive cost. They inherit desirable properties such as anonymity, envy‐freeness, Maskin monotonicity, and population monotonicity from the serial mechanism. We calculate the “maximal efficiency loss” and “maximal manipulation” of α‐serial mechanisms and point out a trade‐off between these two properties.     

Public choice versus constitutional economics: A methodological interpretation of the Buchanan research program

Through conceptual redirections, the Buchanan research program attempts to react to the fact that economic policy advice is often ignored. In terms of positive analyses, the research perspective is focused on institutions, i.e., the rules of economic as well as political games. In terms of normative analyses, the democratic criterion of unanimous consent is substituted for the normative efficiency criterion employed by welfare economics. The underlying idea is to direct positive analyses toward developing informative explanations on which normative analyses can build in order to provide intellectual orientation and thereby to contribute to democratic self-enlightenment. However, large parts of the existing public choice literature can be regarded as empirically oriented welfare-economic analyses of the political sector. Consequently, they run the danger of duplicating the failure of economic policy advice. This is why, during the 80s James Buchanan has changed the name of his research program from public choice to constitutional economics.     

Strategy-proof and individually rational social choice functions for public good economies

Summary This note is to inform about a mistake in my paper (Serizawa, 1996). In that paper, I characterized strategy-proof, individually rational, budget-balancing, non-exploitative and non-bossy social choice functions for economies with one public good and one private good. I established as Theorem 3 (page 507) that a social choice function is strategy-proof, individually rational with respect to endowment, budget-balancing, non-exploitative and non-bossy if and only if it is a scheme of semi-convex cost sharing determined by the minimum demand principle. I also exposed one example (Example 2, page 507) in order to emphasize that non-bossiness is indispensable for this characterization. I claimed that the social choice function in that example satisfies the above axioms except for non-bossiness, and is not a scheme of semi-convex cost sharing. However, the social choice function in the example is actually not strategy-proof, as shown in the simple discussion below. Therefore it is an open question whether or not a similar characterization theorem holds without non-bossiness.I thank Professor Rajat Deb, who kindly pointed out my mistake.     

Local public goods, inter-regional transfers and private information

Suppose that the centre wishes to make transfers between member states of a federation to reduce inequality. However, it lacks precise information concerning the cost differences that are responsible for the initial income inequality. We examine the implications of asymmetric information for the design of the transfer scheme. We show that if member states’ inherent cost levels as local public good providers take discrete values, the first best, or ‘complete information’, transfer scheme may or may not violate incentive compatibility. If inherent cost is a continuous random variable, such a scheme certainly violates incentive compatibility. We also explore the possibility of binding participation constraints. In our model, a binding incentive compatibility constraint leads to a reduction in effort devoted to cost reduction, and a binding participation constraint will also lead to a violation of Samuelson's optimality condition for public good provision.     

After you—endogenous sequencing in voluntary contribution games

We examine contributions to a public good when some donors do not know the true value of the good. If donors in such an environment determine the sequence of moves, two contribution orders may arise as equilibria. Either the uninformed and informed donors contribute simultaneously or the informed contribute prior to the uninformed. Sequential moves result in a larger provision of the public good, because the follower mimics the action of the leader, and in accounting for this response the leader chooses to contribute when it is efficient to do so. An experimental investigation of the game shows that the donors predominantly choose to contribute sequentially, and that the resulting contributions are larger than those of the simultaneous-move game. Although the gain from sequential moves is smaller when the sequence is set exogenously, our results suggest that the involved parties would benefit from having sequential moves imposed upon them.     

Finite supermodular design with interdependent valuations

This paper studies supermodular mechanism design in environments with arbitrary (finite) type spaces and interdependent valuations. In these environments, the designer may have to use Bayesian equilibrium as a solution concept, because ex-post implementation may not be possible. We propose direct (Bayesian) mechanisms that are robust to certain forms of bounded rationality while controlling for equilibrium multiplicity. In quasi-linear environments with informational and allocative externalities, we show that any Bayesian mechanism that implements a social choice function can be converted into a supermodular mechanism that also implements the original decision rule. The proposed supermodular mechanism can be chosen in a way that minimizes the size of the equilibrium set, and we provide two sets of sufficient conditions to this effect. This is followed by conditions for supermodular implementation in unique equilibrium.     

Informational smallness and the scope for limiting information rents

For an incomplete-information model of public-good provision with interim participation constraints, we show that efficient outcomes can be approximated, with approximately full surplus extraction, when there are many agents and each agent is informationally small. The result holds even if agents' payoffs cannot be unambiguously inferred from their beliefs. The contrary result of Neeman [Z. Neeman, The relevance of private information in mechanism design, J. Econ. Theory 117 (2004) 55-77] rests on an implicit uniformity requirement that is incompatible with the notion that agents are informationally small because there are many other agents who have information about them.     

Interim efficient auctions with interdependent valuations

We provide a characterization of interim efficient auctions and examine their properties in the presence of informational interdependent valuations. We show that buyers can be awarded the auctioned item less often than the efficient level. We also show that buyers obtain the item more often as the degree of heterogeneity in preferences increases, even though profitability of trade does not depend on the heterogeneity in preferences.     

Favoritism and reverse discrimination

We analyze the inefficiency that may arise in the form of reverse discrimination in the presence of favoritism or nepotism. Favoritism is typically associated with inefficient transfers to the core support of the incumbent government. But inefficiency that is opposite in nature may also arise through the electoral process in a political environment where favoritism is pervasive. We show that if the policy maker is sufficiently office seeking, a socially efficient action may never be taken if it yields benefits to his core support due to reputational concerns. Hence, the core support of the incumbent may fare worse than other groups. We also consider the implications of policies such as anti-nepotism laws or term limits in the presence of favoritism.     

Reliability of individual valuations of public and private goods: Choice consistency, response time, and preference refinement

We examined the reliability of a large set of paired comparison value judgments involving public goods, private goods, and sums of money. As respondents progressed through a random sequence of paired choices they were each given, their response time decreased and they became more consistent, apparently fine-tuning their responses, suggesting that respondents tend to begin a hypothetical value exercise with relatively imprecise preferences and that experience in expressing preference helps reduce that imprecision. Reliability was greater for private than for public good choices, and greater for choices between a good and a monetary amount than for choices between two goods. However, the reliability for public good choices was only slightly lower than for the private goods.     

Role of honesty in full implementation

This paper introduces a new concept of full implementation that takes into account agents’ preferences for understanding how the process concerning honest reporting works. We assume that the agents have intrinsic preferences for honesty in the sense that they dislike the idea of lying when it does not influence their welfare but instead goes against the intention of the central planner. We show that the presence of such preferences functions in eliminating unwanted equilibria from the practical perspective, even if the degree of the preference for honesty is small. The mechanisms designed are detail free and involve only small fines.     

Stable partnerships, matching, and local public goods

In the presence of local public goods differences in tastes are an important determinant of the way in which partnerships are formed. Heterogeneity in tastes for private vs. public goods produces a tendency to positive assortment and partnerships of couples with similar tastes; heterogeneity in tastes for different public goods brings about partnerships of couples with similar tastes only if there is a significant overlap in the distribution of tastes of the two groups to be matched. We show that with two public goods we may get negative assortment, pure positive assortment being only one of many possibilities.     

Limited observability as a constraint in contract design

Limited observability is the assumption that economic agents can only observe a finite amount of information. Given this constraint, contracts among agents are necessarily finite and incomplete in comparison to the ideal complete contract that we model as infinite in detail. We consider the extent that finite contracts can approximate a complete contract. The objectives of the paper are: (i) to identify properties of agents’ preferences that determine whether or not finiteness of contracts causes significant inefficiency; (ii) to evaluate the performance of finite contracts against the ideal optimal contract in a bilateral bargaining model.     

Group decision-making in the shadow of disagreement

A model of group decision-making is studied, in which one of two alternatives must be chosen. While agents differ in their preferences over alternatives, everybody prefers agreement to disagreement. Our model is distinguished by three features: private information regarding valuations, differing intensities in preferences, and the option to declare neutrality to avoid disagreement. There is always an equilibrium in which the majority is more aggressive in pushing its alternative, thus enforcing their will via both numbers and voice. However, under general conditions an aggressive minority equilibrium inevitably makes an appearance, provided that the group is large enough. Such equilibria invariably display a “tyranny of the minority”: the increased aggression of the minority always outweighs their smaller number, leading to the minority outcome being implemented with larger probability than the majority alternative. We fully characterize the asymptotic behavior of this model as group size becomes large, and show that all equilibria must converge to one of three possible limit outcomes.