Strategy-proofness and efficiency in a simple production economy

We consider an economy with two agents, “firm” and “worker.” The firm owns a technology which transforms a single input into a single output and the worker owns a limited amount of input good, for example, leisure. The firm is interested in profit measured in terms of output and the worker's preferences are defined over the input-output space. Manipulability comes not only from a lack of information about the (worker's) preferences but also about the technology. With a possibility for manipulation, can we still obtain efficient allocations? We show that there is no allocation mechanism which is Pareto efficient, strategy-proof, and non-dictatorial. Received: 30 March 1998/Accepted: 06 July 1999     

Welfare Sharing Within Households: Identification from Subjective Well-being Data and the Collective Model of Labor Supply

The paper proposed a novel approach to identifying intra-household allocations in households with two decision-makers. We addressed the issue by using the collective model of labor supply. Most empirical studies based on the collective approach were restricted to the identification of the sharing rule guiding individual allocations up to a constant. We suggested using individual welfare satisfaction data as an additional source of identification. An empirical example was given using the Russian Longitudinal Monitoring Survey. The sharing rule was found to be related to the spouses’ wage and age differences and number of children. Sharing varied with the level of household income: In low-income households, sharing was equal; in middle (high) income households men held a slight (strong) advantage.     

Money-metric utilitarianism

We discuss a method of ranking allocations in economic environments which applies when we do not know the names or preferences of individual agents. We require that two allocations can be ranked with the knowledge only of agents present, their aggregate bundles, and community indifference sets—a condition we refer to as aggregate independence. We also postulate a basic Pareto and continuity property, and a property stating that when two disjoint economies and allocations are put together, the ranking in the large economy should be consistent with the rankings in the two smaller economies (reinforcement). We show that a ranking method satisfies these axioms if and only if there is a probability measure over the strictly positive prices for which the rule ranks allocations on the basis of the random-price money-metric utilitarian rule. This is a rule which computes the money-metric utility for each agent at each price, sums these, and then takes an expectation according to the probability measure.     

Trade-off between equity and efficiency in a general economy with indivisible goods

In most of the recent literature on fair allocation in economies with indivisible goods and a single infinitely divisible good, it is assumed that each agent can consume at most one indivisible good. In this paper, we show that if this assumption is dropped, there do not necessarily exist envy-free and Pareto efficient allocations. However, envy-free allocations still exist and so do Pareto efficient allocations. Hence, a trade-off between equity and efficiency arises.     

Resource-monotonic solutions to the problem of fair division when preferences are single-peaked

We consider the problem of fairly allocating an infinitely divisible commodity among a group of agents with single-peaked preferences. We search for solutions satisfying resource-monotonicity, the requirement that all agents be affected in the same direction when the amount to divide changes. Although there are resource-monotonic selections from the Pareto solution, there are none satisfying the distributional requirements of no-envy or individual rationality from equal division. We then consider the weakening of resource-monotonicity obtained by allowing only changes in the amount to divide that do not reverse the direction of the inequality between the amount to divide and the sum of the preferred amounts. We show that there is essentially a unique selection from the solution that associates with each economy its set of envy-free and efficient allocations satisfying this property of one-sided resource-monotonicity: it is the uniform rule, a solution that has played a central role in previous analyses of the problem.     

DO RENT‐SEEKING GROUPS ANNOUNCE THEIR SHARING RULES?

We study collective rent seeking between two groups in which each group has the option of releasing or not its sharing‐rule information. First, we show that the case where both groups release their sharing‐rule information never occurs in equilibrium; when the players are unevenly matched, one group releases its sharing‐rule information and the other does not. Then, we select the Pareto‐superior equilibrium when the players are unevenly matched. We show that, in this selected equilibrium, the underdog releases its sharing‐rule information, and the favorite does not; thus, the underdog becomes the leader, and the favorite the follower (JEL D72).     

Collusion, renegotiation and implementation

We study the implementation problem for exchange economies when agents can renegotiate the outcome assigned by the planner and can collude. We focus on the use of sequential mechanisms and present a simple sufficient condition for implementation with renegotiation in strong perfect equilibrium. We present an application to optimal risk sharing, showing that the possibility of collusion and renegotiation does not in general prevent the implementation of efficient allocations. Received: 27 August 1997/Accepted: 29 October 1998     

Existence of efficient envy-free allocations of a heterogeneous divisible commodity with nonadditive utilities

This paper studies the existence of Pareto optimal, envy-free allocations of a heterogeneous, divisible commodity for a finite number of individuals. We model the commodity as a measurable space and make no convexity assumptions on the preferences of individuals. We show that if the utility function of each individual is uniformly continuous and strictly monotonic with respect to set inclusion, and if the partition matrix range of the utility functions is closed, a Pareto optimal envy-free partition exists. This result follows from the existence of Pareto optimal envy-free allocations in an extended version of the original allocation problem.     

The unique informational efficiency of the competitive mechanism in economies with production

The purpose of this paper is to investigate the informational requirements of resource allocation processes for convex production economies. First, we establish a lower bound of the message space of an informationally decentralized mechanism that realizes Pareto efficient allocations over the class of classical production economies. Then, it is shown that this lower bound is exactly the size of the message space of the competitive (Walrasian) mechanism, and thus the competitive mechanism is informationally efficient for general neoclassical production economies in the sense that it uses the smallest message space among the class of resource allocation processes that are informationally decentralized and realize Pareto optimal allocations. Further, it is shown that the competitive mechanism is the unique informationally efficient decentralized mechanism that realizes Pareto efficient and individually rational allocations. The results obtained in the paper may shed light on the socialist controversy between Mises-Hayek and Lange-Lerner.I wish to thank an anonymous referee and the participants at the 2001 Decentralization Conference for valuable comments. This is a reversion of an earlier paper entitled, “The Competitive Mechanism is the Unique Informationally Efficient Process for Economies with Production”. Financial support from the Texas Advanced Research Program as well as from the Bush Fellow Summer Research Program, the Private Enterprise Research Center, and the Lewis Faculty Fellowship at Texas A&M University is gratefully acknowledged.

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The ordinal egalitarian bargaining solution for finite choice sets

Rubinstein et al. (Econometrica 60:1171–1186, 1992) introduced the Ordinal Nash Bargaining Solution. They prove that Pareto optimality, ordinal invariance, ordinal symmetry, and IIA characterize this solution. A feature of their work is that attention is restricted to a domain of social choice problems with an infinite set of basic allocations. We introduce an alternative approach to solving finite social choice problems using a new notion called the Ordinal Egalitarian (OE) bargaining solution. This suggests the middle ranked allocation (or a lottery over the two middle ranked allocations) of the Pareto set as an outcome. We show that the OE solution is characterized by weak credible optimality, ordinal symmetry and independence of redundant alternatives. We conclude by arguing that what allows us to make progress on this problem is that with finite choice sets, the counting metric is a natural and fully ordinal way to measure gains and losses to agents seeking to solve bargaining problems.     

On fairness and welfare analysis under uncertainty

This paper investigates the role of fairness, uncertainty, and a “veil of ignorance” in efficient resource allocation. It focuses on the choice of private and public goods, the method of financing, as well as the choice of information available for public decision-making. A fair-equivalent and Pareto efficient allocation is presented using a maximin criterion defined in terms of individual willingness-to-pay. The paper investigates the role of information in public decision making in terms of its implications for both efficiency and fairness. While better information typically generates improved efficiency, it can also contribute to unfair allocations. The effects of asymmetric information are discussed. Received: 4 May 1998/Accepted: 28 February 2002 We would like to thank two anonymous referees for very useful comments on an earlier draft of the paper. The research was supported in part by a Hatch grant from the University of Wisconsin, Madison.     

Generic efficiency and collusion-proofness in exchange economies

The purpose of this paper is to study the kind of efficient allocations that can be achieved in exchange economies with asymmetric information, by means of a decentralized mechanism robust to coalitional, strategic deviations. To this end, we define a new strategic equilibrium concept – called strong collusion-proof contract – designed to characterize stable communication agreements in games with differential information against non-binding, self-enforcing and incentive compatible deviations by coalitions. We then construct a strategic market mechanism which, for quasi-linear economies, is such that its strong collusion-proof contracts generically induce the incentive compatible interim efficient allocations. Moreover, we show that these allocations can be achieved by strong collusion-proof contracts. We show that the internally consistent extension of the strong collusion-proof contracts generically yields the same set of efficient allocations. Received: 22 January 2001/Accepted: 15 April 2002 RID="*" ID="*"  This author was working at CORE when this paper was written. We wish to thank Claude d'Aspremont, David Martimort, Jean-Fran?ois Mertens and Heracles Polemarchakis for helpful comments on an earlier version. The usual disclaimer applies.     

A voluntary participation game through a unit-by-unit cost share mechanism of a non-excludable public good

The strategic analysis of voluntary participation in the public good provision has shown two distinct results. First, when the provision of public goods is binary, there are Nash equilibria supporting efficient allocations, and these are Strong Nash equilibria of the game. On the other hand, a model of a continuous public good (Saijo–Yamato, J Econ Theory 84:227–242, 1999) showed that the participation of all agents is not an equilibrium in many situations. This article considers the provision of a discrete and multi-unit public good, and examines a unit-by-unit participation game. Namely, people are asked to participate in each unit of public good provision, and those who chose to participate share the marginal cost of public good. In this game of public good provision, there are subgame-perfect equilibria that are Pareto efficient. We also use the refinement concepts to eliminate inefficient subgame-perfect equilibria and also to characterize the efficient subgame-perfect equilibria.     

p-Weakly constrained Pareto efficiency and aggregation in incomplete markets

This paper studies aggregation and a weak form of optimality referring to the p-weakly constrained Pareto efficiency (p-WE) in stochastic finance economies with incomplete markets. We derive a representative agent utility function maximized at equilibrium and a characterization of the set of p-WE allocations. Moreover, we establish the correspondence between the set of competitive equilibrium allocations and the set of p-WE allocations. It is noted that these are accomplished for general time-state utility functions and without restrictions on the initial resource allocations.     

Equity and efficiency in non-convex economies

The objective of this paper is to consider the following question. Does the presence of increasing returns introduce a fundamental trade-off between equity and efficiency objectives? We show that if the no-envy notion of Foley (1967) is taken as the equity criterion and Pareto optimality as the efficiency criterion, then the answer is yes; there exist economies with increasing returns and well-behaved preferences (and no agent-specific inputs) in which there do not exist any envy-free and Pareto optimal allocations. We also propose a weakening of the no-envy criterion and prove that this weaker equity notion is compatible with Pareto optimality in general non-convex economies.     

Coalitionally strategy-proof social choice correspondences and the Pareto rule

This paper studies coalitional strategy-proofness of social choice correspondences that map preference profiles into sets of alternatives. In particular, we focus on the Pareto rule, which associates the set of Pareto optimal alternatives with each preference profile, and examine whether or not there is a necessary connection between coalitional strategy-proofness and Pareto optimality. The definition of coalitional strategy-proofness is given on the basis of a max–min criterion. We show that the Pareto rule is coalitionally strategy-proof in this sense. Moreover, we prove that given an arbitrary social choice correspondence satisfying the coalitional strategy-proofness and nonimposition, all alternatives selected by the correspondence are Pareto optimal. These two results imply that the Pareto rule is the maximal correspondence in the class of coalitionally strategy-proof and nonimposed social choice correspondences.     

A NONEQUILIBRIUM ANALYSIS OF UNANIMITY RULE, MAJORITY RULE, AND PARETO

It is widely held that in the absence of transaction costs unanimity rule is more effective at producing Pareto improvements and Pareto optimal outcomes than majority rule. We compare unanimity rule and majority rule in their ability to adhere to the Pareto criterion and to select Pareto-optimal alternatives using a single-dimensional spatial voting model without rational proposals. This produces two interesting results. First, if proposals are random, then majority rule is almost always more adept at selecting Pareto-optimal alternatives than unanimity rule. Second, if individuals propose their ideal points, then majority rule selects Pareto-optimal outcomes at least as well as unanimity rule. These results contrast with equilibrium analyses, which typically show that unanimity rule is the best voting procedure for maintaining Pareto optimality. (JEL D7 , C61 )     

Strategy-proof division with single-peaked preferences and individual endowments

We consider the problem of (re)allocating the total endowment of an infinitely divisible commodity among agents with single-peaked preferences and individual endowments. We propose an extension of the so-called uniform rule and show that it is the unique rule satisfying Pareto optimality, strategy-proofness, reversibility, and an equal-treatment condition. The resulting rule turns out to be peaks-only and individually rational: the allocation assigned by the rule depends only on the peaks of the preferences, and no agent is worse off than at his individual endowment. Received: 8 September 1995/Accepted: 30 October 1996     

Nash implementation and the bargaining problem

We study Nash implementation of the bargaining solutions in a cake sharing set up. We argue that the minimal Pareto optimal, symmetric and Nash implementable SBS is the one inducing all Pareto optimal and midpoint-dominating utility vectors in each state.     

Collective and Unitary Models: A Clarification

In this note we identify and clarify a confusion that has arisen in the literature about the exact relationship between unitary and collective models and what enters the Pareto weight and the sharing function. We suggest that we should denote as ‘unitary’ any model that leads to outcomes that satisfy the Slutsky conditions whether or not these outcomes depend on distribution factors. In particular, income pooling is neither necessary nor sufficient for a unitary model. We also show that the presence of prices or total expenditure in the sharing rule cannot be used as a test for a unitary model.