The Market Instinct: The Demise of Social Preferences for Self-Interest

Environmental policy design has much to gain from a better understanding of existing voluntary behaviour and motivations. In laboratory experiments, participants often exhibit social preferences such as altruism, spite, reciprocity and notions of fairness. In contrast, traditional neoclassical theory assumes that people act rationally in a way that maximises their self-interest. In environmental markets, social preferences and self-interest interact. We apply experimental economics to test the hypothesis that social preferences are not maintained in the presence of a competitive market institution. In the initial public goods game, many participants were prepared to make costly voluntary contributions. However the introduction of the market institution triggered a ‘market instinct’ in experimental participants. They abandoned the social preferences they were previously expressing and became self-interested profit maximisers. This self-interested behaviour persisted even after the market institution was discontinued. These findings are important to understanding the role and impact of markets for environmental policy.     

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.     

Gamson's Law versus non-cooperative bargaining theory

We compare Gamson's Law, a popular empirical model of legislative bargaining, with two non-cooperative bargaining models in three players divide the dollar games in which no player has enough votes to form a winning coalition on their own. Both of the game theoretic models better organize the comparative static data resulting from changes in nominal bargaining power than does Gamson's Law. We also identify deviations from the point predictions of the non-cooperative bargaining models. Namely, proposer power is not nearly as strong as predicted under the Baron–Ferejohn model, and a significant number of bargaining rounds tend to take more than two steps under demand bargaining and more than one stage under Baron–Ferejohn, counter to the models' predictions. Regressions using the experimental data provide results similar to the field data, but fail to do so once one accounts for predictions regarding coalition composition under Gamson's Law.     

The control of game form recognition in experiments: understanding dominant strategy failures in a simple two person “guessing” game

This paper focuses on instructions and procedures as the reasons that subjects fail to behave according to the predictions of game theory in two-person “guessing game” (beauty contest game) experiments. In this game, two individuals simultaneously choose a number between 0 and 100. The winner is the person whose chosen number is the closest to 2/3 of the average of the two numbers. The weakly dominant strategy is zero. Because of the simplicity of the game, the widespread failure of subjects to choose the weakly dominant strategy has been interpreted as evidence of some fundamental inability to behave strategically. By contrast, we find that subjects’ behavior reflects a lack of understanding of the game form, which we define as the relationships between possible choices, outcomes and payoffs. To a surprising degree, subjects seem to have little understanding of the experimental environment in which they are participating. If subjects do not understand the game form, the experimental control needed for testing game theory is lost. The experiments reported here demonstrate that the failure to act strategically is related to how the game is presented. We test how well subjects are able to recognize the game under a variety of different presentations of the game. Some subjects fail to recognize the game form when it is presented abstractly. When the game is transformed into a simple isomorphic game and presented in a familiar context, subjects do choose weakly dominant strategies. While our results confirm the ability of subjects to make strategic decisions, they also emphasize the need to understand the limitations of experimental subjects’ ability to grasp the game as the experimenter intends. Given these limitations, we provide suggestions for better experimental control.     

What's in a name? Anonymity and social distance in dictator and ultimatum games

The standard procedure in experimental economics maintains anonymity among laboratory participants, yet many field interactions are conducted with neither complete anonymity nor complete familiarity. When we are involved in interactive situations in the field, we usually have some clues concerning the characteristics of others; however, in some environments (such as e-commerce) these clues may not be very substantial. How will people respond to varying degrees of anonymity and social distance? We consider the effect of one form of social distance on behavior by comparing the standard procedure of playing dictator and ultimatum games with the same games played by participants who knew the family name of their counterparts. When these names were revealed, dictators allocated a significantly larger portion of the pie. However, this information had no significant effect on the offers in the ultimatum game, as it appears that strategic considerations crowd out impulses toward generosity or charity.     

基于非合作博弈的期货市场策略分析

本文基于非合作博弈的方法,通过建立非合作博弈模型对期货市场多空双方的行动策略进行分析,分别就完全信息博弈、不完全信息博弈和不完美信息博弈三种不同的博弈环境,讨论了多空双方在不同的市场形势下的行动策略、博弈的均衡及结果。分析结果表明在不同的博弈环境下,无论是均势市场、多头市场还是空头市场,资金和信息对于期货市场多空双方的博弈策略具有至关重要的影响。基于此结论,本文进一步提出,为了获得资金优势和信息优势,建立期货投资基金,形成博弈联盟是一种有效的博弈形式,以此为基础的合作博弈分析方法是分析联盟博弈的有效方法。     

Fragility of information cascades: an experimental study using elicited beliefs

This paper examines the occurrence and fragility of information cascades in two laboratory experiments. One group of low informed participants sequentially guess which of two states has been randomly chosen. In a matched pairs design, another group of high informed participants make similar guesses after having observed the guesses of the low informed participants. In the second experiment, participants’ beliefs about the chosen state are elicited. In equilibrium, low informed players who observe an established pattern of identical guesses herd without regard to their private information whereas high informed players always guess according to their private information. Equilibrium behavior implies that information cascades emerge in the group of low informed participants, the belief based solely on cascade guesses is stationary, and information cascades are systematically broken by high informed participants endowed with private information contradicting the cascade guesses. Experimental results show that the behavior of low informed participants is qualitatively in line with the equilibrium prediction. Information cascades often emerge in our experiments. The tendency of low informed participants to engage in cascade behavior increases with the number of identical guesses. Our main finding is that information cascades are not fragile. The behavior of high informed participants differs markedly from the equilibrium prediction. Only one-third of laboratory cascades are broken by high informed participants endowed with private information contradicting the cascade guesses. The relative frequency of cascade breaks is 15% for the situations where five or more identical guesses are observed. Participants’ elicited beliefs are strongly consistent with their own behavior and show that, unlike in equilibrium, the more cascade guesses participants observe the more they believe in the state favored by those guesses.     

The Impact of Exchange Context on the Activation of Equity in Ultimatum Games

In this paper we report the results of additional exchange ultimatum game experiments conducted at the same time as the exchange ultimatum game experiments reported in Hoffman et al. (Games and Economic Behavior, 7(3), pp. 346–380, 1994). In these additional experiments, we use instructions to change an impersonal exchange situation to a personal exchange situation. To do this, we prompt sellers to consider what choices their buyers will make. Game theory would predict that thinking about the situation would lead sellers to make smaller offers to buyers. In contrast, we find a significant increase in seller offers to buyers. This result suggests that encouraging sellers to thinking about buyer choices focuses their attention on the strategic interaction with humans who think they way they do in personal exchange situations, and who may punish them for unacceptable behavior, and not on the logic of the game theoretic structure of the problem.     

A strategic implementation of the Average Tree solution for cycle-free graph games

In this note we provide a strategic implementation of the Average Tree solution for zero-monotonic cycle-free graph games. That is, we propose a non-cooperative mechanism of which the unique subgame perfect equilibrium payoffs correspond to the average hierarchical outcome of the game. This mechanism takes into account that a player is only able to communicate with other players (i.e., to make proposals about a division of the surplus of cooperation) when they are connected in the graph.     

Separating the Hawks from the Doves: Evidence from continuous time laboratory games

Human players in our laboratory experiment received flow payoffs over 120 seconds each period from a standard Hawk–Dove bimatrix game played in continuous time. Play converged closely to the symmetric mixed Nash equilibrium under a one-population matching protocol. When the same players were matched in a two-population protocol with the same bimatrix, they showed clear movement towards an asymmetric (and very inequitable) pure Nash equilibrium of the game. These findings support distinctive predictions of evolutionary game theory.     

Gaining power through enlargement: Strategic foundations and experimental evidence

Power indices suggest that adding new members to a voting body may affect the balance of power between the original members even if their number of votes and the decision rule remain constant. Some of the original members may actually gain even if voters are bargaining over a fixed budget. We show that this phenomenon can occur as an equilibrium of a non-cooperative bargaining game based on the Baron and Ferejohn (1989) model of legislative bargaining. We implement this game in the laboratory and find that power can be gained by adding new members as the theory predicts.     

THE REVELATION OF INFORMATION THROUGH THE ELECTORAL PROCESS: AN EXPLORATORY ANALYSIS*

This paper investigates the incentives for candidates to make informative campaign speeches concerning their policy intentions. Electoral competition is modeled as a game of communication in which candidates’policy preferences are private information and they compete by making pre-electoral policy announcements. An equilibrium is shown to exist in which candidates reveal their true policy intentions. We find that campaign messages are more likely to be informative, the less powerful is the elected office, the more attractive are candidates’opportunities outside of office, and the more uniform are candidates’prior beliefs as to the median voter's preferred policy.     

集体信誉的理论分析——组织内部逆向选择问题

建立在重复博弈模型上的逆向选择问题称为信誉理论,该理论主要研究博弈参与者如何通过树立信誉实现在非合作博弈中的合作均衡。传统的信誉理论涉及的多是个体的信誉问题,但是当个体信息无法传递时,个体信誉便无法发挥作用。此时,公众通常会对拥有相同标识的集体形成一个整体判断,与个体利益相关的是他们拥有的集体信誉。本文考察了集团内部存在不同类型个体时集体信誉维护的问题,本文称为内部逆向选择问题。我们发现,由于个体利益与集体利益的差异,导致集体信誉的激励作用要弱于传统的个体信誉的作用。此外,由于集体利益与社会利益的不一致,最终即使可以有效激励集团成员最大限度地维护集体利益,如果公众信念更新相对麻木,仍会造成经济运行无效率。     

Do sellers offer menus of contracts to separate buyer types? An experimental test of adverse selection theory

In the basic adverse selection model, a seller makes a contract offer to a privately informed buyer. A fundamental hypothesis of incentive theory is that the seller may want to offer a menu of contracts to separate the buyer types. In the good state of nature, total surplus is not different from the symmetric information benchmark, while in the bad state, private information may be welfare-reducing. We have conducted a laboratory experiment with 954 participants to test these hypotheses. While the results largely corroborate the theoretical predictions, we also find that private information may be welfare-enhancing in the good state.     

Promises and lies: can observers detect deception in written messages

We design a laboratory experiment to examine predictions of trustworthiness in a novel three-person trust game. We investigate whether and why observers of the game can predict the trustworthiness of hand-written communications. Observers report their perception of the trustworthiness of messages, and make predictions about the senders’ behavior. Using observers’ decisions, we are able to classify messages as “promises” or “empty talk.” Drawing from substantial previous research, we hypothesize that certain factors influence whether a sender is likely to honor a message and/or whether an observer perceives the message as likely to behonored: the mention of money; the use of encompassing words; and message length. We find that observers have more trust in longer messages and “promises”; promises that mention money are significantly more likely to be broken; and observers trust equally in promises that do and do not mention money. Overall, observers perform slightly better than chance at predicting whether a message will be honored. We attribute this result to observers’ ability to distinguish promises from empty talk, and to trust promises more than empty talk. However, within each of these two categories, observers are unable to discern between messages that senders will honor from those that they will not.     

Individual behavior of first-price auctions: The importance of information feedback in computerized experimental markets

This article reports the results of an individual choice experiment designed to test the Nash equilibrium predictions of the first-price sealed-bid auction. A subject faced in 100 auctions always the same resale value and competed with computer-simulated bids. The design used between-subjects variation and involved information feedback as the treatment variable. Earlier experimental work on first price auctions has frequently reported an overbidding relative to the risk neutral Nash equilibrium. Our data provide evidence that overbidding can be fostered by the standard information feedback in auction experiments, which, after each auction, reveals the winning bid only. By means of learning direction theory we explain the individual bidding dynamics in our experiment. Finally we apply impulse balance theory and make long run predictions of individual bidding behavior.     

Rationality of weather predictions and insurance purchases: testing the gambler’s and hot hand fallacies

Deviations from the rational behaviour assumed in many economic models have been found in a variety of settings. Two such deviations, the gambler’s and hot hand fallacies have been found in lab settings, as well as in consequential real-world decisions. Previous economic experiments have shown that the behaviour of professionals can differ from that of the general population. In this paper, we use data from two experiments conducted with a particular group of professionals who make yearly high-stakes decisions in the face of uncertain weather and market conditions: agricultural producers. In the experiments, participants were asked to make predictions about the coming year’s weather and market conditions and make decisions in a familiar decision context. Results indicate evidence of the gambler’s fallacy, such that participants were less likely to predict a good outcome if the previous outcome(s) were good. We also observe that participants were more likely to gamble if a previous gamble was successful, but find no impact on two successful gambles. These combined results indicate that even professionals with many years of experience can exhibit behaviours that deviate from those assumed by classical models.     

Testing static game theory with dynamic experiments: A case study of public goods

Game theory provides predictions of behavior in many one-shot games. On the other hand, most experimenters usually play repeated games with subjects, to provide experience. To avoid subjects rationally employing strategies that are appropriate for the repeated game, experimenters typically employ a “random strangers” design in which subjects are randomly paired with others in the session. There is some chance that subjects will meet in multiple rounds, but it is claimed that this chance is so small that subjects will behave as if they are in a one-shot environment. We present evidence from public goods experiments that this claim is not always true.     

The tragedy of the commons revisited: The importance of group decision-making

We use a laboratory experiment to compare the way groups and individuals behave in an inter-temporal common pool dilemma. The experimental design distinguishes between a non-strategic problem where players (individuals or groups of three) make decisions without interaction and a strategic part where players harvest from a common pool. This allows us to correct for differences between individuals and groups in the quality of decisions when testing for differences in competitiveness. Group decisions are either made by majority rule or unanimity. The results show that groups are less myopic than individuals (i.e., they make qualitatively better decisions) but that they are more competitive than individuals when placed in a strategic setting. The net result for groups deciding by majority rule is that they make less efficient decisions in the strategic game than individuals do. We are able to show that this is caused by the median voter departing from her original preference in early periods with a shrinking pool. When groups have to make unanimous decisions they start playing the strategic game more efficiently then individuals do, but they rapidly become more competitive with repetition of the game.     

Rapacious Resource Depletion,Excessive Investment and Insecure Property Rights: A Puzzle

For a country fractionalized in competing factions, each owning part of the stock of natural exhaustible resources, or with insecure property rights, we analyze how resources are transformed into productive capital to sustain consumption. We allow property rights to improve as the country transforms natural resources into capital. The ensuing power struggle about the control of resources is solved as a non-cooperative differential game. Prices of resources and depletion increase faster than suggested by the Hotelling rule, especially with many competing factions and less secure property rights. As a result, the country substitutes away from resources to capital too rapidly and invests more than predicted by the Hartwick rule. The theory suggests that power struggle boosts output but depresses aggregate consumption and welfare, especially in highly fractionalized countries with less secure property rights. Also, adjusted net saving estimates calculated by the World Bank using market prices over-estimate welfare-based measures of genuine saving. Since our theory suggests that genuine saving is zero while empirically they are negative in resource-rich, fractionalized countries, we suggest ways of resolving this puzzle.