What to maximize if you must

The assumption that decision makers choose actions to maximize their preferences is a central tenet in economics, often justified formally or informally by appealing to evolutionary arguments. In contrast, we show that in almost every game and for almost every family of distortions of a player's actual payoffs, some degree of this distortion is beneficial to the player, and will not be driven out by any evolutionary process involving payoff-monotonic selection dynamics. Consequently, under any such selection dynamics the population will not converge to payoff-maximizing behavior. We also show that payoff-maximizing behavior need not prevail when preferences are imperfectly observed.     

国际战略联盟类型选择的演化博弈分析

国际战略联盟类型影响联盟绩效及其稳定发展。以合作偏好度作为选择构建联盟类型的依据,分别考虑无形收益和不考虑无形收益,建立了合作偏好度的演化博弈模型,并由此分析联盟类型的选择:不考虑无形收益,则构建纵向联盟,且演化稳定的合作偏好度随产品互补性增加而增强;考虑无形收益,构建横向或纵向联盟皆可,但需调节自己的合作偏好度,以影响对方的合作偏好度,从而促进联盟的稳定发展。     

Socioeconomic stratification and stereotyping: lab-in-the-field evidence from Colombia

In this study, we test the hypothesis that the Colombian system of socioeconomic stratification (SES), which ranks dwellings from one to six to calculate utility (public services) rates, may induce discrimination. To this end, a field experiment with around 1000 participants from Bogotá is carried out. The design includes a combination of a trust game and a dictator game and SES-contingent decisions. Results exclude the presence of pure preferences for discrimination, yet they confirm that low strata are associated with stereotypes of low trustworthiness. We also observe significant prosocial behavior in the low-income population, and most strikingly, we do not observe any difference in trustworthiness across different income levels.     

Trust and reciprocity in inter-individual versus inter-group interactions: The effects of social influence, group dynamics, and perspective biases

Using an experimental trust game, I examine whether the perspectives and behavior of group representatives and consensus groups differ from those of the same individuals in an analogous inter-individual situation. A primary goal of this research is to extend past work on trust and reciprocity by examining the impact of the social contexts within which social interactions are characteristically embedded. Specifically, this research concerns whether norms and dynamics of trust and reciprocity differ in the contexts of inter-individual and inter-group interactions. First, I examine whether dynamics of trust and reciprocity differ in various inter-group interactions where inter-group decisions are operationalized as 1) autonomous group representatives, i.e., individuals who are given the responsibility of unilaterally making a decision on behalf of a three-person group engaging with a group representative of another such group; and 2) consensus groups, i.e., group members making a consensus trust or reciprocity decision for their groups via a collective process with another such group. Results of these studies show that 1) people trust less and reciprocate less when responsible for a group or organizational decision as autonomous group representatives; 2) consensus groups do not differ from individuals in their level of trust but show dramatically less reciprocity. The group consensus mechanism in fact produced by far the lowest reciprocity level, significantly lower than that exhibited by either individuals or autonomous group representatives. Thus, inter-group trust and reciprocity dynamics are not readily inferable from their inter-individual counterparts. Moreover, an important implication is emerging here: the extent and direction of the discrepancy between individual and group choices in regard to trust and reciprocity levels and possibly other social preferences in general may depend importantly on the precise details of the group decision-making mechanism, for example whether decisions are made consensually, by majority vote, or by a group leader or representative. In addition to examining the level of trust and reciprocity that occur in these various situations, I also studied, using both behavioral and questionnaire data, the roles of self-interest, social influence, and group dynamics in trust and reciprocity perceptions and behavior. The results showed that there exist discrepancies between behavioral forecasts and the actual behavior, and that trusting behavior is driven strongly by expectation of level of reciprocation, while reciprocating behavior is driven strongly by the difference between trust expectation and actual trust received.     

Beliefs and Public Good Provision with Anonymous Contributors

We analyze a static game of public good contributions where finitely many anonymous players have heterogeneous preferences about the public good and heterogeneous beliefs about the distribution of preferences. In the unique symmetric equilibrium, the only individuals who make positive contributions are those who most value the public good and who are also the most pessimistic; that is, according to their beliefs, the proportion of players who most like the public good is smaller than it would be according to any other possible belief. We predict whether the aggregate contribution is larger or smaller than it would be in an analogous game with complete information and heterogeneous preferences, by comparing the beliefs of contributors with the true distribution of preferences. A trade‐off between preferences and beliefs arises if there is no individual who simultaneously has the highest preference type and the most pessimistic belief. In this case, there is a symmetric equilibrium, and multiple symmetric equilibria occur only if there are more than two preference types.     

Interdependent Preferences and Groups of Agents

An individual's preferences are assumed to be malleable and may be influenced by the preferences of others. Mutual interaction among individuals whose preferences are interdependent powers a dynamic process in which preference profiles evolve over time. Two formulations of the dynamic process are presented. One is an abstract model in which the iteration of a mapping from profiles to profiles defines a discrete time dynamic process; the other is a linear discrete time process specified in more detail. Examples motivate the model and illustrate its application. Conditions are given for the existence of a stable preference profile—a rest point of the dynamic process. A stable profile is naturally associated with a division, not in general unique, of the set of agents into subgroups with the property that preference interdependencies within a subgroup are "stronger" than those across subgroups. The conventional case in which each agent's preference relation is exogenously given is, in this model, the special case where each subgroup consists of just one agent.     

The Selection of Preferences Through Imitation

The paper presents a model in which a population of agents repeatedly play games against nature; the rules of behaviour followed are revised over time through a process of imitation. For binary decisions, imitation selects rules consistent with a preference relation of the kind proposed by SSB utility theory and regret theory. In general, this preference relation need not satisfy either independence or transitivity; we state conditions on imitation necessary for it to do so. For decisions over three or more options, the long-run tendency is for options that are maximally preferred in terms of SSB preferences to be chosen. If no maximally preferred option exists, the process of imitation may not converge.     

Evolutionary selection of ‘chivalrous’ conventions in coordination games without common expectations

We study an evolutionary game-theoretic model where players have to choose within a predetermined set of mixed strategies in a coordination game. Players are of two different kinds, male and female. No common expectations assumption is made; players tend therefore to adopt the strategy that yields larger than average expected payoffs for their kind. In this framework, every stable stationary point of the population dynamics can be interpreted as the emergence of a particular convention. A classification of the possible conventions is provided; conditions for their emergence are determined.     

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.

     

The Right Choice at the Right Time: A Herding Experiment in Endogenous Time

Herding describes the phenomenon in decision-making where an economic agent disregards his own private information to follow the actions of his predecessors as in Banerjee (1992). With later decision-makers simply copying earlier decisions their private information cannot be inferred by other decision-makers and will be forever lost. There is some experimental evidence on simple sequential herding of this type in the literature, notably Anderson and Holt (1997). This paper differs by allowing subjects to delay their decision-making in order to benefit from observing others' actions as in more recent herding models such as Chamley and Gale (1994). The results in this paper suggest that subjects will indeed delay when their private information is not sufficiently strong. Despite this ability to wait, as predicted in the theoretical literature, cascades remained ubiquitous and more worrying still, reverse-cascades occurred in which incorrect decisions made by early decision-makers produced informational cascades on the wrong action. In an alternative design, informing subjects that they had made incorrect choices only made matters worse as subjects moved further away from rational behavior.     

Is there selection bias in laboratory experiments? The case of social and risk preferences

Laboratory experiments are frequently used to examine the nature of individuals’ social and risk preferences and inform economic theory. However, it is unknown whether the preferences of volunteer participants are representative of the population from which the participants are drawn, or whether they differ due to selection bias. To answer this question, we measured the preferences of 1,173 students in a classroom experiment using a trust game and a lottery choice task. Separately, we invited all students to participate in a laboratory experiment using common recruitment procedures. To evaluate whether there is selection bias, we compare the social and risk preferences of students who eventually participated in a laboratory experiment to those who did not, and find that they do not differ significantly. However, we also find that people who sent less in a trust game were more likely to participate in a laboratory experiment, and discuss possible explanations for this behavior.     

Environmental Policy Theory Given Bounded Rationality and Other-regarding Preferences

Established environmental policy theory is based on the assumption of homo economicus. This means that people are seen as fully rational and acting in a self-regarding manner. In line with this, economics emphasizes efficient policy solutions and the associated advantages of price incentives. Behavioral economics offers alternative, more realistic views on individual behavior. In this paper we investigate opportunities to integrate bounded rationality and other-regarding preferences into environmental policy theory to arrive at recommendations for more effective policies. For this purpose, we will address decisions made under risk and uncertainty, intertemporal choice, decision heuristics, other-regarding preferences, heterogeneity, evolutionary selection of behaviors, and the role of happiness. Three aspects of environmental policy are considered in detail, namely sustainable consumption, environmental valuation and policy design. We pay special attention to the role of non-pecuniary, informative instruments and illustrate the implications for climate policy.     

Trust and reciprocity behavior and behavioral forecasts: Individuals versus group-representatives

Individuals are often given the responsibility of making decisions on behalf of a group or an organization. However, little is known about preferences or behavior in such contexts. In an adapted trust game, I examine whether the perspectives and behavior of group-representatives differ from those of the same individuals in an analogous situation. Group-representatives are given the responsibility of unilaterally and privately making a decision on behalf of a three-person group. Results from both the main and the follow-up studies show that people trust less and reciprocate less as group-representatives, and thus demonstrate that the interindividual-intergroup discontinuity effect not only exists in group behavior but also in individual behavior of group-representatives. Moreover, results show that trusting behavior is driven by reciprocity expectations, while reciprocating behavior is not sensitive to the first mover's behavior, i.e., the level of trust experienced.     

Identity,Utility, and Cooperative Behaviour: An Evolutionary Perspective*†

This paper provides an argument for the advantage of a preference for identity‐consistent behaviour from an evolutionary point of view. Within a stylized model of social interaction, it is shown that the development of cooperative social norms is greatly facilitated if the agents possess a preference for identity‐consistent behaviour. As compliance with cooperative norms (in the long run) has a positive effect on the agents’ pay‐offs, it is argued that such a preference is evolutionarily advantageous. Notably, the argument, which assumes that agents always act in accordance with their preferences, also accounts for the cost of those features that are crucial for the selection process.     

Evolutionary stability of discrimination under observability

We study the evolution of preferences under perfect and almost perfect observability in symmetric 2-player games. We demonstrate that if nature can choose from a sufficiently general preference space, which includes preferences over outcomes that may depend on the opponent's preference-type, then, in most games, only discriminating preferences (treating different types of opponents differently in the same situation) can be evolutionary stable and some discriminating types are stable in a very strong sense in all games. We use these discriminating types to show that any symmetric outcome which gives players more than their minmax value in material payoffs (fitness) can be seen as equilibrium play of a player population with such strongly stable preferences.     

How to identify trust and reciprocity

This paper uses a three-games (or triadic) design to identify trusting and reciprocating behavior. A large literature on single-game trust and reciprocity experiments is based on the implicit assumption that subjects do not have altruistic or inequality-averse other-regarding preferences. Such experimental designs test compound hypotheses that include the hypothesis that other-regarding preferences do not affect behavior. In contrast, experiments with the triadic design do discriminate between transfers resulting from trust or reciprocity and transfers resulting from other-regarding preferences that are not conditional on the behavior of others. Decomposing trust from altruism and reciprocity from altruism or inequality aversion is critical to obtaining empirical information that can guide the process of constructing models that can increase the empirical validity of game theory.     

Competitive experience and gender difference in risk preference,trust preference and academic performance: Evidence from Gaokao in China

This study examines whether and how competitive experience affects gender difference in the preferences for risk and trust as well as academic performance. By utilizing the provincial differences in college admission rates as an indicator of competitive experience for students, we assess its relationship with gender difference in risk preference, trust preference, and academic performance. We find that females from provinces with lower college admission rates are more risk averse and less trustful, and perform better in more competitive environment, compared with their male counterparts. Our study suggests that observed gender differences may partially reflect the effects of schooling environment rather than inherent gender traits.     

Bounding preference parameters under different assumptions about beliefs: a partial identification approach

We show how bounds around preferences parameters can be estimated under various levels of assumptions concerning the beliefs of senders in the investment game. We contrast these bounds with point estimates of the preference parameters obtained using non-incentivized subjective belief data. Our point estimates suggest that expected responses and social preferences both play a significant role in determining investment in the game. Moreover, these point estimates fall within our most reasonable bounds. This suggests that credible inferences can be obtained using non-incentivized beliefs.     

Evolutionary stability of discrimination under observability

We study the evolution of preferences under perfect and almost perfect observability in symmetric 2-player games. We demonstrate that if nature can choose from a sufficiently general preference space, which includes preferences over outcomes that may depend on the opponent's preference-type, then, in most games, only discriminating preferences (treating different types of opponents differently in the same situation) can be evolutionary stable and some discriminating types are stable in a very strong sense in all games. We use these discriminating types to show that any symmetric outcome which gives players more than their minmax value in material payoffs (fitness) can be seen as equilibrium play of a player population with such strongly stable preferences.     

The politics of special purpose trust funds

Over the last decades, bilateral donors of foreign aid have increased their use of special purpose trust funds to provide earmarked aid to multilateral organizations. This paper investigates the incentives and consequences underlying this recent shift toward country‐ or theme‐specific funding and away from bilateral and multilateral aid. We propose a game‐theoretic model with multiple principals and a multilateral agent to study how the interaction between donor preferences, voter concerns in the donor country, the voting rules at the multilateral organization, and the presence of special purpose trust funds influences aid allocation. We show that multilateral organizations with majority rules are more likely to receive discretion and thus voluntary core contributions than those with unanimity requirements and that the possibility of earmarking multilateral aid decreases donors’ contributions to the multilateral's discretionary core budget and the amount of bilateral aid. In contrast to much of the literature dealing with issues of delegation and bi‐ and multilateral aid, our model suggests non‐monotonic effects of preference heterogeneity on the choice of aid channel for some parameter combinations when contributions to special purpose trust funds are an option.