The role of role uncertainty in modified dictator games

We compare behavior in modified dictator games with and without role uncertainty. Subjects choose between a selfish action, a costly surplus creating action (altruistic behavior) and a costly surplus destroying action (spiteful behavior). While costly surplus creating actions are the most frequent under role uncertainty (64%), selfish actions become the most frequent without role uncertainty (69%). Also, the frequency of surplus destroying choices is negligible with role uncertainty (1%) but not so without it (11%). A classification of subjects into four different types of interdependent preferences (Selfish, Social Welfare maximizing, Inequity Averse and Competitive) shows that the use of role uncertainty overestimates the prevalence of Social Welfare maximizing preferences in the subject population (from 74% with role uncertainty to 21% without it) and underestimates Selfish and Inequity Averse preferences. An additional treatment, in which subjects undertake an understanding test before participating in the experiment with role uncertainty, shows that the vast majority of subjects (93%) correctly understand the payoff mechanism with role uncertainty, but yet surplus creating actions were most frequent. Our results warn against the use of role uncertainty in experiments that aim to measure the prevalence of interdependent preferences.     

The ABC mechanism: an incentive compatible payoff mechanism for elicitation of outcome and probability transformations

When it comes to experiments with multiple-round decisions under risk, the current payoff mechanisms are incentive compatible with either outcome weighting theories or probability weighting theories, but not both. In this paper, I introduce a new payoff mechanism, the Accumulative Best Choice (“ABC”) mechanism that is incentive compatible for all rational risk preferences. I also identify three necessary and sufficient conditions for a payoff mechanism to be incentive compatible for all models of decision under risk with complete and transitive preferences. I show that ABC is the unique incentive compatible mechanism for rational risk preferences in a multiple-task setting. In addition, I test empirical validity of the ABC mechanism in the lab. The results from both a choice pattern experiment and a preference (structural) estimation experiment show that individual choices under the ABC mechanism are statistically not different from those observed with the one-round task experimental design. The ABC mechanism supports unbiased elicitation of both outcome and probability transformations as well as testing alternative decision models that do or do not include the independence axiom.

     

Social preferences and moral biases

An emerging consensus in economics is that three motives are at work in strategic decisions: distributive preferences, reciprocal preferences and self-interest. An important obstacle, however, has been moral biases: distortions created by self-interest can obscure our measures of social preferences. This paper describes a simple experiment to address this. We compare the decisions of implicated “stakeholders” with those of impartial “spectators.” We find that stakeholders are less inclined to respond to the generosity of others than are spectators. We also clarify a result in previous research [e.g., Offerman, T., 2002. Hurting hurts more than helping helps. European Economic Review 46, 1423–1437] that stakeholders punish unkindness more than they reward kindness. We find that this asymmetry in reciprocity has two sources: an asymmetry in the underlying preference that even impartial spectators display and a moral bias; stakeholders punish more and reward less than spectators. In sum, we find that all three motives have important and significant effects on final allocations.     

Existence of nonatomic core-walras allocations

We prove the existence of Walras allocations, where allocations are understood as measures on a nonatomic Boolean algebra. The algebra need not be a σ-algebra, as usually assumed, and the measures need not be countably additive and need not have densities with respect to the endowment allocation. Except for a strengthening of the continuity hypothesis, this is the framework we used earlier to prove the equivalence of core and Walras allocations. Our proof rests on two propositions of special interest in their own right: one asserts extensibility of coalition preferences, and the other characterizes coalition preferences.     

Employee types and endogenous organizational design: An experiment

When managers are sufficiently guided by social preferences, incentive provision through an organizational mode based on informal implicit contracts may provide a cost-effective alternative to a more formal mode based on explicit contracts and active monitoring. This paper reports the results from a stylized laboratory experiment designed to test whether subjects in the role of firm owner rely on the social preferences of other (‘employee’) subjects with whom they are matched when choosing which payoff version of a simple trust game these employee subjects should play (‘the organizational mode’). Our main finding is that they do so, albeit in a different way than theory predicts. The importance of the first mover's social preferences for trusting behavior is recognized by the owner subjects, but the significant (first order) impact second movers’ social preferences have on trusting behavior of first movers seems to be overlooked.     

Farmers’ performance and subject pool effect in decentralized bargaining markets

We report results from a decentralized bargaining market experiment conducted with farmers and students. Our results indicate that despite its bad reputation, performance is highly efficient (although not as efficient as the competitive equilibrium prediction). Farmers and students perform similarly regarding quantities, prices, and allocative efficiencies, but not regarding payoff allocations between buyers and sellers.     

Conditional cooperation in a sequential move game

Cooperation is a pervasive social phenomenon, but more often than not economic theories have little to say about its causes and consequences. In this paper, we explore the hypothesis that cooperative behaviour might be motivated by pure self-interest when the “social” payoff in a game is increasing. We report the results of a series of experiments on the Centipede game. The experiments are organised in two subsequent steps. Subjects first participate in a 2-period trust game, randomly matched with unknown partners. We apply the strategy method in order to elicit their social preferences. On the basis of their pre-game behaviour, individuals are divided into three main social groups: selfish individuals, pure altruists and reciprocators. At the second step of the experiment, subjects play a repeated 6-move Centipede game with an increasing final payoff. Each subject plays twice, in a low and in a high-stake Centipede game, and he/she is informed about his/her co-player social preferences. We provide statistical evidence to identify the origin of cooperation within homogeneous and heterogeneous social groups. We construct a Poisson regression model to assess the determinants of the duration of conditional cooperation in the Centipede.     

Existence and fairness of value allocation without convex preferences

Shafer (Econometrica, 48 (1980), 467–476) proved that in a finite exchange economy value allocations exist, provided that each agent has convex, complete, transitive, compact and monotone preferences. However, if preferences are not convex, then value allocations may not exist. To remedy this difficulty we enlarge the set of value allocations by introducing the concept of approximate value allocations, and show that in a finite exchange economy approximate value allocations exist, even if preferences are not convex, or compact, or monotone. This value existence result can be used to provide a very general value existence theorem for a sequence of finite economies. Further, we show that value allocations may discriminate in favor of or against a coalition of agents.     

Pareto optima and equilibria when preferences are incompletely known

An exchange economy in which agents have convex incomplete preferences defined by families of concave utility functions is considered. Sufficient conditions for the set of efficient allocations and equilibria to coincide with the set of efficient allocations and equilibria that result when each agent has a utility in her family are provided. Welfare theorems in an incomplete preferences framework therefore hold under these conditions and efficient allocations and equilibria are characterized by first order conditions.     

A Non-cooperative Approach to Bankruptcy Problems

We propose an elementary game form that allows to obtain the allocations proposed by any acceptable bankruptcy rule as the unique payoff vector of the corresponding Nash equilibria.     

Social identity and preferences over redistribution

We design an experiment to study the effects of social identity on preferences over redistribution. The experiment highlights the trade-off between social identity concerns and maximization of monetary payoffs. Subjects belonging to two distinct natural groups are randomly assigned gross incomes and vote over alternative redistributive tax regimes, where the regime is chosen by majority rule. We find that a significant subset of the subjects systematically deviate from monetary payoff maximization towards the tax rate that benefits their group when the monetary cost of doing so is not too high. These deviations cannot be explained by efficiency concerns, inequality aversion, reciprocity, social learning or conformity. Finally, we show that behavior in the lab helps explain the relationship between reported income and stated preferences over redistribution observed in survey data.     

Risk attitudes and the stag-hunt game

A stag-hunt game (with the risky and safe actions) has two pure Nash equilibria that are Pareto-rankable. The risky action leads either to the Pareto-superior equilibrium (high payoff) or to out of equilibrium (low payoff) depending on the opponent’s action. Both players may want to obtain high payoff but uncertainty about the opponent’s action may prevent them to take such strategic risk. This paper investigates how information about the risk attitude of an opponent affects a player’s action choice in the stag-hunt game. I find that although a subject’s propensity to choose the risky action depends on her opponent’s risk attitude, it does not depend on her own risk attitude.     

Optimal growth with many consumers

A method is described for constructing all Pareto-optimal allocations for a dynamic economy with many heterogeneous consumers, under certainty, in which both the technology and consumer preferences are recursive but preferences need not be additively separable over time. Optimal (perfect foresight competitive equilibrium) allocations are obtained through the study of a dynamic program. For an economy with one consumption good, sufficient conditions are given for the existence of a unique interior stationary distribution of consumption and wealth. For a two-person exchange economy, sufficient conditions are given for the global asymptotic stability of the unique interior stationary point.     

Fast or fair? A study of response times

This paper uses a modified dictator game to investigate the relationship between response times and social preferences. We find that faster subjects more often chose the option with the highest payoff for themselves. Moreover, our within-analysis reveals that, for a given individual, payoff maximizing choices are reached quicker than choices expressing social preferences.     

PREFERENCES UNDER IGNORANCE

A decision maker (DM) makes choices from different sets of alternatives. The DM is initially ignorant of the payoff associated with each alternative and learns these payoffs only after a large number of choices have been made. We show that, in the presence of an outside option, once payoffs are learned, the optimal choice rule from sets of alternatives can be rationalized by a DM with strict preferences over all alternatives. Under this model, the DM has preferences for preferences while being ignorant of what preferences are “right.”     

Efficient allocations under ambiguity

Important implications of the expected utility hypothesis and risk aversion are that if agents have the same probability belief, then consumption plans in every efficient allocation of resources under uncertainty are comonotone with the aggregate endowment, and if their beliefs are concordant, then the consumption plans are measurable with respect to the aggregate endowment. We study these two properties of efficient allocations for models of preferences that exhibit ambiguity aversion using the concept of conditional beliefs, which we introduce in this paper. We provide characterizations of such conditional beliefs for the standard models of preferences used in applications.     

Searching for religious discrimination among childcare workers

We implement a lab‐in‐the‐field experiment among childcare workers in Chandigarh, India, to evaluate discriminatory attitudes of the Hindu workers toward Muslim children. We use a third‐party allocation game that controls for selfish payoff‐maximizing preferences across the treatments and focus exclusively on distributional attitudes. Our results indicate that the workers in our sample are primarily motivated by welfare‐based criteria in making their allocation decisions and do not practice discrimination based on religious identities.     

The set of sunspot equilibria in economies with incomplete financial markets: variable asset prices

Summary. I consider the set of equilibria of two-period economies with S extrinsic states of nature in the second period and I assets with linearly independent nominal payoffs. Asset prices are variable. If the number of agents is greater than (S-I), the payoff matrix is in general position and S 2I, the set of equilibrium allocations generically (in utility function space) contains a smooth manifold of dimension (S-1). Moreover, the map from states o f nature to equilibrium allocations (restricted to this manifold) is one-to-one at each equilibrium. Received: February 23, 1998; revised version: June 1, 2000     

Competitive outcomes and the inner core of NTU market games

We consider the inner core as a solution concept for cooperative games with non-transferable utility (NTU) and its relationship to payoffs of competitive equilibria of markets that are induced by NTU games. An NTU game is an NTU market game if there exists a market such that the set of utility allocations a coalition can achieve in the market coincides with the set of utility allocations the coalition can achieve in the game. In this paper, we introduce a new construction of a market based on a closed subset of the inner core which satisfies a strict positive separability. We show that the constructed market represents the NTU game and, further, has the given closed set as the set of payoff vectors of competitive equilibria. It turns out that this market is not uniquely determined, and thus, we obtain a class of markets. Our results generalize those relating to competitive outcomes of NTU market games in the literature.     

The Effectiveness of Distributive Policy in a Competitive Economy

I consider an abstract social system made of individual owners endowed with nonpaternalistic interdependent preferences, who interact by means of individual gifts and by exchanges on competitive markets. The existence of equilibrium is established. I identify the set of allocations that are decentralizable in the sense that they are general equilibria for some vectors of market prices and initial endowments. This set is characterized in a simple way from the social endowment and individual market and distributive preferences. Decentralizable allocations are all accessible to distributive policy, unless public transfers are confined to some neighborhood of 0. In the latter case, distributive policy remains free to perform local redistributions of wealth across the components of the graph of equilibrium gifts.