Charness et al. (2007b) have shown that group membership has a strong effect on individual decisions in strategic games when group membership is salient through payoff commonality. In this comment, I show that their findings also apply to nonstrategic decisions, even when no outgroup exists, and I relate the effects of group membership on individual decisions to joint decision making in teams. I find in an investment experiment that individual decisions with salient group membership are largely the same as team decisions. This finding bridges the literature on team decision making and on group membership effects.

Using new methods, we measure the intensities of higher-order risk preferences (prudence and temperance) in an incentivized experiment with 658 adolescents. Aligned with theory, we find that higher-order risk preferences are strongly related to field behavior, including prevention, health, addictive behavior, and financial decision-making. Most importantly, we show that ignoring prudence and temperance can yield misleading conclusions about the relation of risk preferences to field behavior, and that survey measures of risk tolerance often relate to field behavior because they capture higher-order risk preferences.

Credence goods markets are characterized by asymmetric information between sellers and consumers that may give rise to inefficiencies, such as under- and overtreatment or market breakdown. We study in a large experiment with 936 participants the determinants for efficiency in credence goods markets. While theory predicts that liability or verifiability yield efficiency, we find that liability has a crucial, but verifiability at best a minor, effect. Allowing sellers to build up reputation has little influence, as predicted. Seller competition drives down prices and yields maximal trade, but does not lead to higher efficiency as long as liability is violated.

The need for efficient coordination is ubiquitous in organizations and industries. The literature on the determinants of efficient coordination has focused on individual decision making so far. In reality, however, teams often have to coordinate with other teams. We present a series of coordination experiments with a total of 1,101 participants. We find that teams of three subjects each coordinate much more efficiently than individuals. This finding adds one important cornerstone to the recent literature on the conditions for successful coordination. We explain the differences between individuals and teams using the experience weighted attraction learning model.

We study risk attitudes, ambiguity attitudes, and time preferences of 661 children and adolescents, aged ten to eighteen years, in an incentivized experiment and relate experimental choices to field behavior. Experimental measures of impatience are found to be significant predictors of health-related field behavior, saving decisions, and conduct at school. In particular, more impatient children and adolescents are more likely to spend money on alcohol and cigarettes, have a higher body mass index, are less likely to save money, and show worse conduct at school. Experimental measures for risk and ambiguity attitudes are only weak predictors of field behavior.