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.     

Comparing Bargaining Solutions in the Shadow of Conflict: How Norms against Threats Can Have Real Effects

In many economic environments agents make costly and irreversible investments (in “guns”) that may enhance their respective threat payoffs but also shrink the utility possibilities set. In such settings, with variable threats and a variable utility possibilities set, it becomes possible to rank different bargaining solutions in terms of efficiency. We compare bargaining solutions within a class in which the influence of the threat point on the bargaining outcome varies across solutions. Under symmetry, we find that the solution in which the threat point is least influential—the equal sacrifice solution—Pareto-dominates the other solutions. Since the equal sacrifice solution puts the least weight on the threat point, norms against threats (that can be seen in many seemingly rhetorical pronouncements in adversarial relations) can mitigate some of the costs of conflict and therefore have efficiency-enhancing effects. Journal of Economic Literature Classification Numbers: C72, C78, D30, D70, D72, K42.     

Competitive bargaining equilibrium

In a simple exchange economy we propose a bargaining procedure that leads to a Walrasian outcome as the agents become increasingly patient. The competitive outcome therefore obtains even if agents have market power and are not price-takers. Moreover, where in other bargaining protocols the final outcome depends on bargaining power or relative impatience, the outcome here is determinate and depends only on preferences and endowments. Our bargaining procedure involves bargaining over prices and maximum quantity constraints, and it guarantees convergence to a Walrasian outcome for any standard exchange economy. In contrast, without quantity constraints we show that equilibrium is generically inefficient.     

The Efficiency Principle in Non-Cooperative Coalitional Bargaining

Applying the non-cooperative theory of coalitional bargaining, I examine a widely held view in economic literature that an efficient outcome can be agreed on in voluntary bargaining among rational agents in the absence of transaction costs. While this view is not always true, owing to the strategic formation of subcoalitions, I show that it can hold under the possibility of successive renegotiations of agreements. Renegotiation may, however, motivate bargainers to form a subcoalition first and to exploit the first-mover rent. This strategic behaviour in the process of renegotiation may distort the equity of an agreement.
JEL Classification Numbers: C72, C78, D23, D61, D63.     

Surplus Sharing with a Two‐Stage Mechanism

In this article we consider environments where agents jointly produce a private output good by contributing privately owned resources. An efficient outcome may not be realized due to strategic behavior and conflicting interests of the agents. We construct a two‐stage mechanism, building on a Varian mechanism. The modified mechanism ensures an equilibrium for a large class of preferences and guarantees the feasibility of outcomes.     

Plea bargaining: on the selection of jury trials

We consider a model of the criminal court process, focusing on plea bargaining. A plea bargain provides unequal incentives to go to trial because innocent defendants are more willing to plead not guilty. We show that the court process implements the preferences of the person or group who is most concerned about wrongful conviction. If a prosecutor is more concerned about wrongful conviction than the jury, the prosecutor can shape the defendant pool at trial so that jurors act according to prosecutor’s preferences against judicial mistakes. Our model also connects insights from strategic jury models that usually omit plea bargaining with the actual criminal court process where most cases are resolved through plea bargaining. As an example, we show that the inferiority of the unanimity rule established in Feddersen and Pesendorfer (Am Polit Sci Rev 92(1):23–35, 1998) persists in spite of the addition of plea bargaining.     

Parimutuel contests with strategic risk-sensitive bettors

Existing models in the parimutuel betting literature typically explain betting data by either assuming a single, representative bettor with certain risk preferences or by assuming that a number of risk neutral bettors compete strategically within a game theoretic framework. We construct a theoretical framework of parimutuel markets in which we model both strategic interaction and individual bettor risk preferences, distinguishing between sophisticated insiders and recreational outsiders. We solve this model analytically for the optimal insider betting amount in a static symmetric Nash equilibrium. A new data set of 126 million individual horse race bets in New Zealand from 2006 to 2014 allows us to calibrate the model. We find that insiders (those betting $100 or more) outperform outsiders by 7.5% in terms of realized returns. The best fit of the model to the data is obtained when insiders are assumed to be risk neutral and to have an information advantage of 0.08 in probability terms. This finding provides empirical support for the common assumption of risk neutrality in strategic interaction models of parimutuel betting.     

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.     

An economic agent in my brain? A critical analysis of multiple-self models in neuroeconomics

Neuroeconomic multiple-self models describe individuals’ choices as the equilibrium of the interaction amongst neural sites modelled as economic agents. This approach aims at explaining some inter-temporal inconsistency problems and the rejection of unfair offers in ultimatum games. However, the experiments on these models do not provide replicable results. The standard view interprets this problem as due to inadequate econometric techniques. Conversely, this paper shows that the non-replicability problem arises from a conundrum of multiple-self models’ (MSMs) theory. It illustrates how the assumption of neuroeconomic agents is deduced from the revealed preferences theory applied to the neuro-level. Therefore, the paper shows how experiments on MSMs cannot test the assumption of neuroeconomic agents but only the empirical hypotheses that derive from it. This entails that the assumption of neuroeconomic agents is a tautology, which might generate hypotheses that do not robustly identify the neural correlates of behaviour.     

Inefficiency and social exclusion in a coalition formation game: experimental evidence

This paper experimentally investigates the impact of reciprocal behavior in multilateral bargaining and coalition formation. Our results show that reciprocal fairness strongly affects the efficiency and equity of coalition formation. In a large majority of cases, inefficient and unfair coalitions are chosen when their coalition values are relatively high. Up to one third of the experimental population is excluded from bargaining and earns nothing. In monetary terms economically significant efficiency losses occur. We find that the interplay of selfish and reciprocal behavior unavoidably leads to this undesirable consequences. We also compare the predictions of recently developed models of social preferences with our experimental results. We find that some of these models capture the empirical regularities surprisingly well.     

Weak stability and a bargaining set for the marriage model

In this note we introduce weak stability, a relaxation of the concept of stability for the marriage model by assuming that the agents are no longer myopic in choosing a blocking pair. The new concept is based on threats within blocking pairs: an individually rational matching is weakly stable if for every blocking pair one of the members can find a more attractive partner with whom he forms another blocking pair for the original matching. Our main result is that under the assumption of strict preferences, the set of weakly stable and weakly efficient matchings coincides with the bargaining set of Zhou (1994, Games Econ. Behav. 6, 512–526) for this context.     

专用性、专有性与企业制度

本文认为 ,虽然剩余索取权和控制权安排是企业制度的重要内容 ,但企业制度的本质却是如何创造和分配组织租金。现有文献往往含混地将“专用性”视为当事人获得组织租金的法理甚至经济基础 ,然而事实上 ,“专用性”不但不是当事人获得组织租金的谈判力基础 ,反而削弱了这一基础。基于此 ,我们提出当事人获得企业组织租金的谈判力基础应该是“专有性” ,并且这一变量极大地影响着企业制度的选择和演变。总之 ,我们认为现实中的企业制度安排并非是社会福利最大化或交易费用最小化的产物 ,而是理性的当事人相互博弈的结果。     

Disability and Economy: A Game Theoretic Approach

This paper takes a game theoretic approach to disability‐related issues by constructing a model that studies the case of hereditary deafness on Martha's Vineyard Island, USA from the seventeenth century to the early years of twentieth, where the island community adjusted itself to the hereditary deafness so that it was not treated as a disability. The model of the present paper has two stages. First of all, there are two types of continua of agents, the deaf and the non‐deaf. In the first stage, the non‐deaf agents become either bilinguals or monolinguals. In the second stage, agents are classified into deaf people, bilinguals and monolinguals. They are then randomly matched to form a trio to play a three‐person bargaining game with infinite horizon, random proposers and language constraints. Two bargaining games are considered. The first one is a majority bargaining game where only two out of three can agree to implement a bargaining outcome. The second one is a unanimity bargaining game where all three agents are required to reach an agreement. The majority game exhibits strategic complementarity, while the unanimity game exhibits strategic substitutability. This paper also takes an inductive approach to examine how prejudice against people with disability may emerge.     

Incomplete preferences and rational intransitivity of choice

Do violations of classical rationality theory imply that agents are acting against their self-interest? To answer this question, we investigate whether completeness and transitivity necessarily hold when agents choose outcome rationally—that is, their choice sequences do not lead to dominated outcomes. We show that, because of the danger of money pumps and other manipulations, outcome rationality implies that agents must have transitive psychological preferences. Revealed preferences, on the other hand, must be complete since agents can be forced to choose from any set of options. But these justifications of transitivity and completeness cannot be combined. We show that if psychological preferences are incomplete then revealed preferences can be intransitive without exposing agents to manipulations or violating outcome rationality. We also show that a specific case of nonstandard behavior, status quo maintenance, is outcome-rational in the simple environments considered in the experimental literature, but not in more complex settings.     

Growth with many agents and wages paid ex ante

In this paper, we consider a one-sector model of economic growth with several infinitely-lived heterogeneous agents, who are endowed with diverse discount factors as well as preferences over consumption. In line with the classical Ramsey model, agents are not allowed to borrow against future income. Unlike the traditional assumption of ex post wage payment, wages are paid ex ante in our model. We first explain the difference between the assumptions of wages being paid ex ante and wages being paid ex post in the framework of a simple illustrative two-class model. Our main result shows that in contrast to the many-agent Ramsey model with ex post wage payment, the capital stock sequence converges to the steady state stock irrespective of production technology employed by the firms. Further, all impatient agents own zero capital stock, whereas the most patient agent owns the entire capital stock from some time onward. Thus, we have shown that a slight modification in the timing of wage payment in growth models can lead to significant changes in the stability properties of equilibrium dynamics.     

On the Problem of Constructing Rational Preferences

In standard models it is typically taken for granted that preferences are given and defined over the alternatives alone, and the possibility of making a rational choice is a matter of assumption. I generalise this aspect of the economic model so that preferences over alternatives are constructed from given preferences defined over various characteristics of the alternatives under consideration. I characterise the decision problem before investigating what conditions a procedure for aggregating preferences over attributes into preferences over alternatives must satisfy in order for the latter to be rational. I then consider what the implications of these conditions for the procedural rationality of the aggregation process.     

Bargaining with endogenous disagreement: The extended Kalai-Smorodinsky solution

Following Vartiainen (2007) we consider bargaining problems in which no exogenous disagreement outcome is given. A bargaining solution assigns a pair of outcomes to such a problem, namely a compromise outcome and a disagreement outcome: the disagreement outcome may serve as a reference point for the compromise outcome, but other interpretations are given as well. For this framework we propose and study an extension of the classical Kalai-Smorodinsky bargaining solution. We identify the (large) domain on which this solution is single-valued, and present two axiomatic characterizations on subsets of this domain.     

The market for preferences

Learning processes are widely held to be the mechanism by whichboundedly rational agents adapt to environmental changes. Weargue that this same outcome might also be achieved by a differentmechanism, namely specialisation and the division of knowledge,which we here extend to the consumer side of the economy. Wedistinguish between high-level preferences and low-level preferencesas nested systems of rules used to solve particular choice problems.We argue that agents, while sovereign in high-level preferences,may often find it expedient to acquire, in a pseudo-market,the low-level preferences in order to make good choices whenpurchasing complex commodities about which they have littleor no experience. A market for preferences arises when environmentalcomplexity overwhelms learning possibilities and leads agentsto make use of other people's specialised knowledge and decisionrules.     

Opacity in bargaining over public good provision

We consider ultimatum bargaining over the provision of a public good. Offer-maker and responder can delegate their decisions to agents whose actual decision rules are opaque. We show that the responder will benefit from strategic opacity, even with bilateral delegation. The incomplete information created by strategic opacity choices does not lead to inefficient negotiation failure in equilibrium. Inefficiencies arise from an inefficient provision level. While an agreement will always be reached, the public good provision will fall short of the socially desirable level. Compared with unilateral delegation, bilateral delegation is never worse from a welfare perspective.     

Bargaining and markets: complexity and the competitive outcome

Rubinstein and Wolinsky (Rev. Econ. Stud. 57 (1990) 63-78) consider a simple decentralised market game in which agents meet randomly or voluntarily and bargain over the terms of trade. They show that any individually rational price can be sustained as a sequential equilibrium even though the model has a unique competitive outcome. Here, I consider Rubinstein and Wolinsky's model and show that if complexity costs of implementing strategies enter players’ preferences, together with the standard payoff in the game, then every equilibrium is stationary/Markov and induces the unique competitive price. Thus, I demonstrate that aversion to complexity may provide a justification for the competitive outcome.