Social dilemmas appear in 2 basic forms: the public goods (PG) problem, in which the individual must decide whether to contribute to a common resource, and the commons dilemma (CD), in which the individual must decide whether to take from a common resource. The 2 forms of choice dilemma are equivalent in terms of outcomes, but because they involve different decision frames, they are not psychologically equivalent. The present experiment, with 88 undergraduates, examined framing effects on decisions involving use of a common resource pool in a 2 × 2 × 2 (PG vs CD task structure × small vs large group size × individualistic vs collective social identity) factorial design. That the 2 versions of the decision task were not psychologically equivalent was evidenced both by a main effect of task structure and by interactions involving task structure, group size, and social identity. Overall, Ss kept more of the common resource for themselves under the PG version of the task than under the CD frame. Under the CD structure, group size had no effect on choice behavior, but in the PG version, Ss in large groups kept more than did individuals in small groups. As the resource pool was depleted, the social identity manipulation had opposite effects for large groups under CD and PG frames.
*Reprinted in Leigh Thompson (Ed.), Key Readings in Organizational Behavior, Psychology Press, 2003.