1. The Commons Dilemma

2. Hardin's (1968) work represents the first major contemporary analysis of the commons dilemma. Harding noted that there are no effective technological solutions to this problem, but only a moral one - mutual coercion, mutually agreed upon.

3. Hardin's "tragedy of the commons" is not really a theory, but rather an "ideal type" (see Weber, 1949). Thus it serves as a useful reference point from which to judge real world collective dilemmas. For social psychologists and sociologists the necessity of tragedy in "resource commons" is an empirical question.

4. Social scientists study, through a variety of means, the critical variables implicated in commons dilemmas, the conditions in which the "tragedy occurs", and conditions that seem to prevent "tragedy" from occurring.

5. Since Hardin's original (1968) article, collective dilemmas have been studied by scholars within a variety of disciplines (e.g. see Hardin and Baden, 1977). It is a central problem that cuts a theoretical swath through the social sciences as well as a number of other disciplines.

6. We will review some of the research findings of experimental social psychology.

7. The Prisoner’s Dilemma

8. Experimental research on collective dilemmas have taken the form of N-person games; these have their roots in the Prisoner’s dilemma.

9. ab cd ConfessNot Confess Payoff Matrix for the Prisoners’ Dilemma Based on Years in Prison. Confess Not Confess First Prisoner Second Prisoner -8-8-10 0 -2 -80 -10 -2

10. The Prisoner’s Dilemma -- A Variation Incorporating Collective Norms.

11. ab cd ConfessNot Confess Payoff Matrix for the Prisoners’ Dilemma Based on Norms and Potential Sanctions. Confess Not Confess First Prisoner Second Prisoner -8-8-10 -2 -8-10 -2

12. The validity of game simulations appears to be an open question. However, many participants seem to get so caught up in the simulations that their behavior resembles that of what one would expect in real world dilemma situations.

13. Information and Communication Information has been identified as an important variable in collective dilemmas (Edney, 1980). In some laboratory research it has been demonstrated that informing participants about the possible consequences of their actions can be effective in preventing commons problems from arising (Stern, 1976).

14. Communication is perhaps the most obvious and most researched variables in this paradigm. It has generally been observed that when games are structured so that participants can communicate with one another, "cooperation" increases.

15. The importance of communication on cooperation seems apparent; communication probably interacts with a number of other variables in affecting cooperation in collective dilemmas (for instance: territories, group size, visibility, trust, and attributions about others behavior;

16. Trust Trust that others will act pro-socially (or lack thereof) is an important factor in collective dilemmas

17. Visibility and Group Size Visibility is a variable which likely interacts with trust in affecting behavior in collective dilemmas. If people's choices are highly visible, their actions are easily evaluated. Others can then respond to the individual's behavior by rewarding or punishing her, or by changing their own behavior.

18. A seemingly related finding is that people in large groups cooperate less than people in small groups. These findings would seem to overlap with the work of Latane' and Darley (1968, 1970) on the diffusion of responsibility. In many collective dilemmas it may not be clear who is responsible, or in fact, if an individual's behavior has a significant impact on a collective outcome.

19. Territories One solution to the commons problem has been to create territories. The creation of territories reduces the number of people exploiting the resource, and in empirical research has been found to increase the size of resource stocks

20. Sanctioning and Organizational Solutions In some real world collective dilemmas, people organize to further their collective interests. In experimental research, several variations of this solution have been examined. For example, Caldwell (1976) found that when subjects are able to punish selfish participants, cooperation increases.

21. Summary Many treatments of collective dilemmas (including Hardin's) have been based on the "rational man" depiction of human nature as espoused in the tenets of classical economic and political theory. Experimental social psychology has broadened the focus by examining the effects of social interaction and cognition in addition to the influence of the payoff structure on behavior.

22. What emerges from the collective dilemma literature is that solutions have to be pursused outside of the assumptions laid down in Hardin's paradigm (see Berkes, 1985). For instance, norms and social values can be established which alter a payoff structure that formerly favored self-interested behavior (Heath, 1976). Further, fines and sanctions can be enforced to support such prosocial norms and values (Yamagishi, 1986, 1988a, 1988b).

23. Collective dilemmas have been studied by social psychologists through gaming approaches in a variable analysis fashion (e.g. examining group size, communication, territories, visibility, etc.).