The behavioral validity of the strategy method in public good experiments

We compare the strategy method and the direct response method in public good experiments in a within-subject design. This comparison is interesting because the strategy method is frequently used to investigate preference heterogeneity. We find that people identified by the strategy method as conditional cooperators also behave as conditional cooperators under the direct response method. Free-rider types contribute systematically less than all others but show the most systematic deviation from the predicted contributions, because they contribute in the first half of the direct response experiment. Overall, our results support the behavioral validity of the strategy method in public good experiments.