Natural experiments, high stakes, expert subjects, knowledge of the precise objectives and exact rules, clean measurement, observability of strategies, incentives, actions and consequences, large datasets, exogenous rule changes, distinct social effects, and no Hawthorne effects. These and other desirable attributes for empirical work are found in sports settings. In sports, features that often characterize either the lab or the field are found simultaneously. Sports can offer the best of both worlds. Reluctance to recognize these advantages reflects a misunderstanding of the virtues of sports data, and this reluctance has discouraged the study of these settings and slowed down the production of knowledge. This survey reviews literature that shows how sports settings have made it possible to implement the first successful test, or the best test to date, of various models and hypotheses, and to discover new phenomena. It is not a question of what economics can do for sports, but what sports can do for economics.

The implications of the Minimax theorem are tested using natural data. The tests use a unique data set from penalty kicks in professional soccer games. In this natural setting experts play a one-shot two-person zero-sum game. The results of the tests are remarkably consistent with equilibrium play in every respect: (i) winning probabilities are statistically identical across strategies for players; (ii) players' choices are serially independent. The tests have substantial power to distinguish equilibrium play from disequilibrium alternatives. These results represent the first time that both implications of von Neumann's Minimax theorem are supported under natural conditions. Copyright The Review of Economic Studies Limited, 2003.

Presents an empirical analysis of the risk properties of human capital returns. Discussion on measures of human capital returns; Description of the mean-variance spanning methodology; Information on real human capital returns and U.S. equity index return for 1964 to 1996.

Emotions can have important effects on performance and socioeconomic outcomes. We study a natural experiment where two teams of professionals compete in a tournament taking turns in a sequence. As the sequential order is determined by the random outcome of a coin flip, the treatment and control groups are determined via explicit randomization. Hence, absent any psychological effects, both teams should have the same probability of winning. Yet, we find a systematic first-mover advantage. Further, professionals are self-aware of their own psychological effects and, when given the chance, they rationally react by systematically taking advantage of these effects.

Understanding when and how individuals think about real-life problems is a central question in economics. This paper studies the role of inertia (inattention), state dependence, and learning. The empirical setting is a tariff experiment, when optional measured tariffs for local telephone calls were introduced unanticipatedly. We find that consumers tend to align their choices of tariff and telephone use levels correctly. Despite low potential savings, mistakes are not permanent, as individuals actively engage in tariff switching in order to reduce the monthly cost of telephone service. Ignoring unobservable heterogeneity and the endogeneity of past choices would have reversed these results.

This paper is concerned with the effect of nonmonetary incentives on behavior, in particular with the study of social pressure as a determinant of corruption. We offer empirical evidence that shows how professional soccer referees favor home teams in order to satisfy the crowds in the stadium. Referees have discretion over the addition of extra time at the end of a soccer game to compensate for lost time due to unusual stoppages. We find that referees systematically favor home teams by shortening close games where the home team is ahead, and lengthening close games where the home team is behind. They show no such bias for games that are not close. We further find that when the rewards for winning games increase, referees change their bias accordingly. Lastly, we identify that the mechanism through which bias operates is to satisfy the crowd, by documenting how the size and composition of the crowd affect referee favoritism.

We study how professional players and college students play zero-sum two-person strategic games in a laboratory setting. We first ask professionals to play a 2 × 2 game that is formally identical to a strategic interaction situation that they face in their natural environment. Consistent with their behavior in the field, they play very close to the equilibrium of the game. In particular, (i) they equate their strategies' payoffs to the equilibrium ones and (ii) they generate sequences of choices that are serially independent. In sharp contrast, however, we find that college students play the game far from the equilibrium predictions. We then study the behavior of professional players and college students in the classic O'Neill 4 × 4 zero-sum game, a game that none of the subjects has encountered previously, and find the same differences in the behavior of these two pools of subjects. The transfer of skills and experience from the familiar field to the unfamiliar laboratory observed for professional players is relevant to evaluate the circumstances under which behavior in a laboratory setting may be a reliable indicator of behavior in a naturally occurring setting. From a cognitive perspective, it is useful for research on recognition processes, intuition, and similarity as a basis for inductive reasoning.

This paper examines the problem of measuring intellectual influence based on data on citations between scholarly publications. We follow an axiomatic approach and find that the properties of invariance to reference intensity, weak homogeneity, weak consistency, and invariance to splitting of journals characterize a unique ranking method. This method is different from those regularly used in economics and other social sciences. Copyright The Econometric Society 2004.

In the centipede game, all standard equilibrium concepts dictate that the player who decides first must stop the game immediately. There is vast experimental evidence, however, that this rarely occurs. We first conduct a field experiment in which highly ranked chess players play this game. Contrary to previous evidence, our results show that 69 percent of chess players stop immediately. When we restrict attention to Grandmasters, this percentage escalates to 100 percent. We then conduct a laboratory experiment in which chess players and students are matched in different treatments. When students play against chess players, the outcome approaches the subgame-perfect equilibrium.

We survey the uses of combinatorial auctions that have been deployed in practice, giving emphasis to their key representational and economic aspects. In addition, we discuss behavioral economics considerations on both the bidder and auctioneer sides of the market, and the interrelated topics of simplicity and trust, highlighting key opportunities for future work.