Behavioral economics has grown significantly in importance and prevalence within the economics profession over the last couple of decades. Most economics departments now include researchers conducting behavioral research, and most economics journals regularly publish behavioral work.

Behavioral economics is generally defined as using evidence and constructs from neighboring social sciences, especially about limits on computation, willpower, and self-interest, to inform economic analysis (e.g., Camerer and Loewenstein, 2003). While many of these constructs come from psychology, other social sciences have much to contribute as well (see Weber and Dawes, 2005). For instance, anthropological research has provided important insights into the understanding of how social institutions and interactions shape strategic behavior (see Henrich et al., 2001).

What motivates people to trust and be trustworthy? Is trust solely “calculative,” based on the expectation of trustworthiness, and trustworthiness only reciprocity? Employing a within-subject design, we run investment and dictator game experiments in Russia, South Africa and the United States. Additionally, we measured risk preferences and expectations of return. Expectations of return account for most of the variance in trust, but unconditional kindness also matters. Variance in trustworthiness is mainly accounted for by unconditional kindness, while reciprocity plays a comparatively small role. There exists some heterogeneity in motivation but people behave surprisingly similarly in the three countries studied.

Both mainstream economics and its critics have focused on models of individual rational agents even though most important decisions are made by small groups. Little systematic work has been done to study the behavior of small groups as decision-making agents in markets and other strategic games. This may limit the relevance of both economics and its critics to the objective of developing an understanding of how most important decisions are made. In order to gain some insight into this issue, this paper compares group and individual economic behavior. The objective of the research is to learn whether there are systematic differences between decisions made by groups and individual agents in market environments characterized by risky outcomes. A quantitative measure of deviation from minimally-rational decisions is used to compare group and individual behavior in common value auctions.

Several non-experimental studies claim that heterogeneity among individuals reduces trust. A few experimental studies have examined the effects of naturally-occurring differences among subjects on trusting behavior, and in contrast, most have not supported these claims. We adopt a novel approach by inducing heterogeneity among subjects in a canonical trust experiment. We accomplish this by varying the show-up payments given to subjects for participating in the experiment. We find that this induced inequality does not consistently affect first- or second-mover behavior in the classic trust game in the manner predicted by either previous theoretical work or empirical studies of survey-based measures of trust. Further, the effect of inequality on trust, in terms of both sign and significance, depends on whether show-up payments are awarded publicly or privately.

In recent work on non-cooperative network formation star-shaped networks play an important role. In a particular theoretical model of Bala and Goyal (2000) center-sponsored stars are the only strict Nash networks. In testing this theoretical model, Falk and Kosfeld (2003) do not find experimental evidence that players select the center-sponsored star. Based on a slight modification of Bala and Goyal's model, we design a network formation experiment in which, depending on link costs, periphery-sponsored stars and the empty network are the only strict Nash networks. We observe that almost all groups not only reach a strict Nash network once but also switch the center player in periphery-sponsored stars several times. The main innovation in our experiment is to use a continuous time framework which we believe to be a more realistic setting to study behavior in network formation situations and which makes coordination on stars much easier than simultaneous strategy adaptation in discrete time.

“Si él lo necesita” (if he really needs it) was the most common argument given by the subjects who accepted the zero offer in the ultimatum game (strategy method) during experiments conducted among illiterate (adult) gypsies in Vallecas, Madrid. Interestingly the acceptance of the zero offer was not a rare case but, in contrast, was the modal value. This is even more remarkable if we consider that the 97% of the subjects proposed the equal split.

Recent experiments have shown that voluntary punishment of free riders can increase contributions, mitigating the free-rider problem. But frequently punishers punish high contributors, creating “perverse” incentives which can undermine the benefits of voluntary punishment.

In our experiment, allowing punishment of punishing behaviors reduces punishment of high contributors, but gives rise to efficiency-reducing second-order “perverse” punishment. On balance, efficiency and contributions are slightly but not significantly enhanced.

Economic models typically allow for “free disposal” or “reversibility” of information, which implies non-negative value. Building on previous research on the “curse of knowledge” we explore situations where this might not be so. In three experiments, we document situations in which participants place positive value on information in attempting to predict the performance of uninformed others, even when acquiring that information diminishes their earnings. In the first experiment, a majority of participants choose to hire informed—rather than uninformed—agents, leading to lower earnings. In the second experiment, a significant number of participants pay for information—the solution to a puzzle—that hurts their ability to predict how many others will solve the puzzle. In the third experiment, we find that the effect is reduced with experience and feedback on the actual performance to be predicted. We discuss implications of our results for the role of information and informed decision making in economic situations.

The substantively rational value of the games studied in this paper does not help predict subject performance in the experiment at all. An accurate model must account for the cognitive ability of the people playing the game. This paper investigates whether the variation in measured rationality bounds is correlated with the probability of winning when playing against another person in games that exceed both players’ estimated rationality bound. Does seeing deeper into a game matter when neither player can see to the end of the game? Subjects with higher measured bounds win 63 percent of the time and the larger the difference the more frequently they win.