This article reviews recent developments in the economic theory of individual decision making under risk. Since the 1950s it has been known that individual choices violate the standard model of expected utility in predictable ways. Considerable research effort has now been devoted to the project of developing a superior descriptive model. Following an overview of non-expected utility theories which distinguishes between “conventional” and “non-conventional” approaches, the paper seeks to assess these alternative models in terms of empirical success (using laboratory and field data) and theoretical usefulness. The closing sections reflect on some new directions emerging in this literature.

A generalized common consequence problem is used to contrast the predictions of expected utility theory and several new theories of choice under uncertainty. An experiment designed to test these predictions is reported. Systematic violations of expected utility theory are detected but, although a consistent pattern emerges from the data, it offers little support for any of the new theories. The analysis is extended to test predictions that are unique to regret theory and significant regret effects are detected.

We introduce group cohesion to study the economic relevance of social relationships in team production. We operationalize measurement of group cohesion, adapting the “oneness scale” from psychology. A series of experiments, including a preregistered replication, reveals strong, positive associations between group cohesion and performance assessed in weak-link coordination games, with high-cohesion groups being likely to achieve superior equilibria. In exploratory analysis, we identify beliefs rather than social preferences as the primary mechanism through which factors proxied by group cohesion influence group performance. Our evidence provides proof of concept for group cohesion as a useful tool for economic research and practice.

The preference reversal phenomenon is usually interpreted as evidence of nontransitivity of preference, but has also been explained as the result of the difference between individuals' responses to choice and valuation problems; the devices used by experimenters to elicit valuations; and the "random lottery selection" incentive system. This paper reports an experiment designed so that none of these factors could generate systematic nontransitivities; yet systematic violations of transitivity were still found. The pattern of violation was analogous with that found in previous preference reversal experiments and is consistent with regret theory.