Cooperation, contributor types, and control questions

A large number of experimental studies use the strategy method procedure introduced by Fischbacher, Gächter, and Fehr (Econ. Lett. 71:397-404, 2001) to measure individuals’ attitudes towards cooperation. The procedure elicits subjects’ strategic-form decisions in a one-shot game and classifies each subject as one of several different contributor types. In this paper, we examine the robustness of the procedure and its capacity to help explain the pattern of contributions observed in a separate, repeated game setting. Overall, we show that the elicited contributor types can explain behavior fairly well in the repeated game. Free-rider types contribute less than conditional cooperators, although we observe evidence consistent with strategic cooperation in the early periods of the repeated game. Nevertheless, by the last period, classified free-rider types converge to pure free-riding behavior. In addition, we highlight a potential methodological concern related to the use of control questions. We find that the inclusion of control questions increases (decreases) the proportion of free rider (conditional cooperator) types, but also leads to substantial wait times for many subjects. This raises concerns about the psychological impact of long wait times, through boredom, frustration, or spite, on the cooperative behavior of subjects in the laboratory setting.