Individual Restraint and Group Efficiency in Commons Dilemmas: The Effects of Two Types of Environmental Uncertainty1


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    This paper was the winner of the 1994 Division 34 Student Paper Award, and was presented at the annual meeting of the American Psychological Association in Los Angeles, August 1994. The authors wish to thank Dee O'Connor, Melanie Geist, and Michael Miller for their valuable assistance, and the Social Sciences and Humanities Research Council of Canada for its support. Donald W. Hine is now at Department of Psychology, Laurentian University, Sudbury, Ontario, Canada.

Correspondence concerning this article should be addressed to Robert Gifford, Department of Psychology, University of Victoria, Victoria, British Columbia V8W 3P5, Canada.


In most real-world commons, the exact resource quantity is rarely known, and the rate at which the resource regenerates is not always predictable. Annual salmon runs, for example, are based on breeding rates and many other factors; those fishing never know exactly how many fish will be available for next year's season. The present study employed a computerized commons dilemma simulation to investigate the impact of uncertainty in pool size and regeneration rate on individuals harvest choice and the efficiency with which groups managed the resource pool. Both types of uncertainty produced significant declines in individual restraint and group efficiency, although the group-level effects tended to be stronger than those at the individual level. Implications for the management of real-world commons are discussed.