Why Do We Need Laboratory Experiments in Political Science?

In this paper, I will provide a general overview of the experimental studies of behavior and outcomes in common-pool resource dilemmas conducted by Roy Gardner, James Walker, and myself, as well as other colleagues at Indiana University, or by colleagues at other universities who have replicated key experimental designs. I will focus primarily on the lessons we have learned from these experiments as a core part of a larger research program combining theoretical developments, field research, and laboratory experiments of relevance to political scientists.In Section 2, common-pool resources and appropriation dilemmas will be defined. Section 3 describes the sparse design we developed for our baseline appropriation experiment to include just the core aspects that underlie appropriation dilemmas in field settings: a non-linear payoff function based on the decisions of more than two appropriators who obtained no information about other subjects' actions.In Section 4, experiments that introduced face-to-face communication are described. In these experiments, subjects were authorized to communicate with one another in a group setting before returning to their terminals to make their own private decisions.Section 5 provides an overview of the series of experiments where we changed the payoff component to allow subjects to sanction one another at a cost to themselves. Since using this option produces a benefit for all at a cost to the individual, the game-theoretic prediction is that no one will choose the costly sanctioning option.Section 6 synthesizes the experiments where we changed the authority rule to allow subjects to covenant with one another to determine their investment levels and to adopt a sanctioning system if they wished