Solving coordination failure with “all-or-none” group-level incentives

Coordinating activity among members is an important problem faced by organizations. When firms, or units within firms, are stuck in bad equilibria, managers may turn to the temporary use of simple incentives—flat punishments or rewards—in an attempt to transition the firm or unit to a more efficient equilibrium. We investigate the use of incentives in the context of the “minimum-effort,” or “weak-link,” coordination game. We allow groups to reach the inefficient equilibrium and then implement temporary, flat, “all-or-none” incentives to encourage coordination on more efficient equilibria. We vary whether incentives are positive (rewards) or negative (penalties), whether they have substantial or nominal monetary value, and whether they are targeted to a specific outcome (the efficient equilibrium) or untargeted (apply to more than one outcome). Overall, incentives of all kinds are effective at improving coordination while they are in place, but there is little long-term persistent benefit of incentives—once incentives are removed, groups tend to return to the inefficient outcome. We find some differences between different kinds of incentives. Finally, we contrast our results to other recent work demonstrating greater long-term effectiveness of temporary incentives.      

Auctions of Heterogeneous Objects

Simultaneous sealed bid auctions of heterogeneous objects are analyzed. Each bidder's reservation value for an object depends upon the other objects he obtains. Bidders' reservation values are common knowledge. In simultaneous first-price auctions, the set of Walrasian equilibrium allocations contains the set of pure strategy Nash equilibrium allocations which in turn contains the set of strict Walrasian equilibrium allocations. Hence, pure strategy Nash equilibria (when they exist) are efficient. Mixed strategy Nash equilibria may be inefficient. In simultaneous second-price auctions, any efficient allocation can be implemented as a pure strategy Nash equilibrium outcome if a Walrasian equilibrium exists.Journal of Economic LiteratureClassification Numbers: D44, D51.     

Implementing efficient graphs in connection networks

We consider the problem of sharing the cost of a network that meets the connection demands of a set of agents. The agents simultaneously choose paths in the network connecting their demand nodes. A mechanism splits the total cost of the network formed among the participants. We introduce two new properties of implementation. The first property, Pareto Nash implementation (PNI), requires that the efficient outcome always be implemented in a Nash equilibrium and that the efficient outcome Pareto dominates any other Nash equilibrium. The average cost mechanism and other asymmetric variations are the only mechanisms that meet PNI. These mechanisms are also characterized under strong Nash implementation. The second property, weakly Pareto Nash implementation (WPNI), requires that the least inefficient equilibrium Pareto dominates any other equilibrium. The egalitarian mechanism (EG) and other asymmetric variations are the only mechanisms that meet WPNI and individual rationality. EG minimizes the price of stability across all individually rational mechanisms.     

Minorities and Endogenous Segregation

A theoretical analysis is proposed of segregation as an equilibrium phenomenon in a random-matching model of the marriage market. Otherwise identical partners possess a pay-off-irrelevant characteristic, colour. We derive the set of colour-blind equilibria and show that they are generically constrained inefficient. Equilibrium segregation strategies are strategies that condition actions on the type of match. It is shown that distributions of types exist such that segregation equilibrium pay-offs Pareto dominate colour-blind pay-offs. For other distributions, segregation also generates conflict, where the majority unambiguously gains, while the minority group may lose. Giving preferential treatment, that is, minority bias, can increase overall welfare.     

International R&D Collaboration and Strategic Trade Policy

We study an international trade model with symmetric countries and symmetric firms, with countries making strategic trade policies, anticipating the decisions of firms on R&D collaboration at the subsequent stage. In general we should observe a conflict between the equilibrium outcome and the efficient one. We find that an asymmetric outcome where one country unilaterally liberalizes trade while the other does not is likely to occur. We also find that while banning international R&D collaboration may help to reach free trade equilibrium in certain situations, it provides little assistance in reaching the outcome that maximizes global welfare.     

Network architecture, salience and coordination

This paper reports the results of an experimental investigation of dynamic games in networks. In each period, the subjects simultaneously choose whether or not to make an irreversible contribution to the provision of an indivisible public good. Subjects observe the past actions of other subjects if and only if they are connected by the network. Networks may be incomplete so subjects are asymmetrically informed about the actions of other subjects in the same network, which is typically an obstacle to the attainment of an efficient outcome. For all networks, the game has a large set of (possibly inefficient) equilibrium outcomes. Nonetheless, the network architecture makes certain strategies salient and this in turn facilitates coordination on efficient outcomes. In particular, asymmetries in the network architecture encourage two salient behaviors, strategic delay and strategic commitment. By contrast, we find that symmetries in the network architecture can lead to mis-coordination and inefficient outcomes.     

Transboundary Environmental Problems with Mobile but Heterogeneous Populations

Most of the literature on transboundaryenvironmental problems treats population ineach country or region as constant, ignoringpopulation mobility. We showed previously thatif there is perfect population mobility betweenregions, and populations are homogeneous, asocially efficient outcome can be supported asa Nash equilibrium of the game of uncoordinatedpolicy setting, even without any internationalenvironmental agreement. In the present paperwe introduce heterogeneous population, and showthat when people differ, a non-cooperativeoutcome is generally inefficient. We alsodemonstrate that for a particular set ofobjective functions for the regionalgovernments, there is an equilibrium of thegame of uncoordinated policy setting that isefficient. Finally, we give an example wherethe decentralized outcome is efficient whenthere is no population mobility, butinefficient when there is population mobility.     

Implementation,Elimination of Weakly Dominated Strategies and Evolutionary Dynamics

This paper studies convergence and stability properties of T. Sjöström's (1994, Games Econom. Behav.6, 502–511) mechanism, under the assumption that boundedly rational players find their way to equilibrium using monotonic evolutionary dynamics and best-reply dynamics. This mechanism implements most social choice functions in economic environments using as a solution concept one round of deletion of weakly dominated strategies and one round of deletion of strictly dominated strategies. However, there are other sets of Nash equilibria, whose payoffs may be very different from those desired by the social choice function. With monotonic dynamics, all these sets of equilibria contain limit points of the evolutionary dynamics. Furthermore, even if the dynamics converge to the “right” set of equilibria (i.e., the one which contains the solution of the mechanism), it may converge to an equilibrium which is worse in welfare terms. In contrast with this result, any interior solution of the best-reply dynamics converges to the equilibrium whose outcome the planner desires. Journal of Economic Literature Classification Numbers: C72, D70, D78.     

Coalitions, agreements and efficiency

If agents negotiate openly and form coalitions, can they reach efficient agreements? We address this issue within a class of coalition formation games with externalities where agents’ preferences depend solely on the coalition structure they are associated with. We derive Ray and Vohra's [Equilibrium binding agreements, J. Econ. Theory 73 (1997) 30-78] notion of equilibrium binding agreements using von Neumann and Morgenstern [Theory of Games and Economic Behavior, Princeton University Press, Princeton, 1944] abstract stable set and then extend it to allow for arbitrary coalitional deviations (as opposed to nested deviations assumed originally). We show that, while the extended notion facilitates the attainment of efficient agreements, inefficient agreements can nevertheless arise, even if utility transfers are possible.     

WELFARE GAINS AND LOSSES IN SUNSPOT EQUILIBRIA*

We study a standard two period exchange economy with one nominal asset. As is well known, there is a continuum of sunspot equilibria around each efficient equilibrium. A sunspot equilibrium is inefficient but some households may gain in sunspot equilibria relative to the efficient equilibrium. We show that a household's equilibrium utility level is either locally maximized or locally minimized at the efficient equilibrium, and derive a condition which identifies whether or not a household's utility is locally minimized or maximized.     

Voluntarily Separable Repeated Prisoner's Dilemma

Ordinary repeated games do not apply to real societies where one can cheat and escape from partners. We formulate a model of endogenous relationships that a player can unilaterally end and start with a randomly assigned new partner with no information flow. Focusing on two-person, two-action Prisoner's Dilemma, we show that the endogenous duration of partnerships generates a significantly different evolutionary stability structure from ordinary random matching games. Monomorphic equilibria require initial trust building, while a polymorphic equilibrium includes earlier cooperators than any strategy in monomorphic equilibria and is thus more efficient. This is due to the non-linearity of average payoffs.     

Do binding agreements solve the social dilemma?

We investigate experimentally whether “binding agreements” can provide a solution to the social dilemma that arises in the presence of pure public goods. Signing a binding agreement can prevent players from free riding on the contributions to the public good. However, a well known theoretical result is that the outcome of the endogenous formation of agreements is not necessarily efficient. Our setting is a bargaining game in which agreements form sequentially. The individual level of contribution to the public good increases with the size of the coalition reaching an agreement and the global agreement is always the socially optimal structure. There are two equilibrium outcomes, the global agreement and an asymmetric structure, which consists of two coalitions of different sizes, the small one free riding on the contributions of the larger one. We run an experiment which lends force to the theoretical result that outcomes may be inefficient. However, subjects do not play Nash and the experimental outcome is, on average, even more inefficient than the theory predicts. Our analysis leads to the conclusion that different types of behaviour co-exist.     

Bargains,Barter, and Money

We examine a search money model in which there is a symmetric coincidence of wants in all barter matches. However, when bargaining outcomes are asymmetric across matches, the barter economy is inefficient. Then a robust monetary equilibrium exists provided that money holders enjoy adequate bargaining terms. Fiat money may be welfare improving. In contrast to the literature, it is the asymmetry in bargains across matches rather than asymmetry in demands that generates these results. Journal of Economic Literature Classification Numbers: C78, E40.     

The taxation of capital returns in overlapping generations models

This paper shows that in the Diamond (1965) overlapping generations economy with production and capital savings, there is a period-by-period balanced fiscal policy supporting a steady state allocation that Pareto-improves upon the laissez-faire competitive equilibrium steady state (whether dynamically inefficient or efficient) without resorting to intergenerational transfers. The policy consists of taxing linearly (or subsidizing, in the dynamically efficient case) the returns to capital, while balancing the budget period by period through a lump-sum transfer (or tax, respectively) in second period. This intervention grants every generation the highest steady state utility attainable through markets (i.e. remunerating factors by their marginal productivities and without transfers) which under laissez-faire is not a competitive equilibrium outcome. A transition from the competitive equilibrium steady state to this other steady state is also Pareto-improving when the former is dynamically inefficient. The result disentangles from redistributive considerations the impact of the taxation of capital returns on steady state welfare, and thus provides a rationale for the taxation of capital returns that is based on efficiency considerations and not on redistributive goals.     

Achieving efficiency with manipulative bargainers

Two agents bargain over the allocation of a bundle of divisible commodities. After strategically reporting utility functions to a neutral arbitrator, the outcome is decided by using a bargaining solution concept chosen from a family that includes the Nash and the Raiffa–Kalai–Smorodinsky solutions. When reports are restricted to be continuous, strictly increasing and concave, it has been shown that this kind of “distortion game” leads to inefficient outcomes. We study the distortion game originated when agents are also allowed to claim non-concave utility functions. Contrasting with the previous literature, any interior equilibrium outcome is efficient and any efficient allocation can be supported as an equilibrium outcome of the distortion game. In a similar fashion to the Nash demand game we consider some uncertainty about the opponent's features to virtually implement the Nash bargaining solution.     

The Efficiency of Direct Public Involvement in Environmental Policymaking: An Experimental Test

In collaborative negotiation, stakeholder representatives are charged with the development of a mutually acceptable set of public policies. Although this approach has become popular in environmental negotiations, little is known about the characteristics of the outcomes that are reached. In this paper, we employ an Edgeworth box framework to investigate the nature of bargaining over public goods (environmental policies) that have multiple attributes. We then design and conduct laboratory experiments within this framework to test whether negotiated outcomes satisfy standard axiomatic bargaining predictions under a variety of conditions. Specifically, we test whether two parties with Pareto inefficient endowments of two goods will trade to Pareto improving and Pareto efficient outcomes, and to the Nash bargain in particular. We vary whether the Nash bargain coincides with or diverges from the outcome that maximizes the joint payoff, or the outcome that equalizes payoffs, and whether subjects are provided full or partial information. We find that bargainers reach Pareto improving and efficient outcomes across treatments, but withdraw support for the Nash bargain when it generates unequal payments or when payoff information is private. We conclude that this experimental framework offers a promising method for studying multi-attribute negotiations.     

How Communication Improves Efficiency in Bargaining Games

We study a double auction with two-sided private information and preplay communication, for which Myerson and Satterthwaite (1983, J. Econ. Theory28, 265–281) showed that all equilibria are inefficient and the Chatterjee–Samuleson linear equilibrium is most efficient. Like several others, we find that players use communication to surpass equilibrium levels of efficiency, especially when the communication is face-to-face. Our main contribution is an analysis of how communication helps the parties achieve such high levels of efficiency. We find that when preplay communication is allowed, efficiency above equilibrium levels is a result of what we call “dyadic” strategies that allow the parties to coordinate on a single price that reflects both parties' valuations. Journal of Economic Literature Classification Numbers: C78, D82.     

Multiplicity in general financial equilibrium with portfolio constraints

This paper explores the role of portfolio constraints in generating multiplicity of equilibrium. We present a simple financial market economy with two goods and two households, households who face constraints on their ability to take unbounded positions in risky stocks. Absent such constraints, equilibrium allocation is unique and is Pareto efficient. With one portfolio constraint in place, the efficient equilibrium is still possible; however, additional inefficient equilibria in which the constraint is binding may emerge. We show further that with portfolio constraints cum incomplete markets, there may be a continuum of equilibria; adding incomplete markets may lead to real indeterminacy.     

Symmetric Tax Competition under Formula Apportionment

This paper compares property taxation to a corporate income tax based on formula apportionment in a model where identical countries compete to attract capital. We find that if countries can pair a residence–based capital tax with a property tax (source tax on capital) the tax equilibrium is efficient. In contrast, the use of a 2–factor FA scheme based on sales and capital combined with a residence–based capital tax leads to an inefficient outcome.     

Designing incentives for online question-and-answer forums

We provide a game-theoretic model of sequential information aggregation motivated by online question-and-answer forums. An asker posts a question and each user decides when to aggregate a unique piece of information with existing information. When the quality exceeds a certain threshold, the asker closes the question and allocates points to users. We consider the effect of different rules for allocating points on the equilibrium behavior. A best-answer rule provides a unique, efficient equilibrium in which all users respond in the first round, for substitutes valuations over information. However, the best-answer rule isolates the least efficient equilibrium for complements valuations. We demonstrate alternate scoring rules that provide an efficient equilibrium for distinct subclasses of complements valuations, and retain an efficient equilibrium for substitutes valuations. We introduce a reasonable set of axioms, and establish that no rule satisfying these axioms can achieve the efficient outcome in a unique equilibrium for all valuations.