Intergroup Competition for the Provision of Binary Public Goods

An experimental paradigm is proposed for investigating interpersonal conflicts under conditions of intergroup competition. The paradigm constitutes an n-person game with imperfect and incomplete information in which the n players arc divided into two groups, are each assigned monetary endowment, and must then decide independently and anonymously whether to keep the endowment or contribute it to the group's benefit. The group with the larger sum of contributions is provided with a monetary reward (binary public good), which is shared equally among all of its members regardless of their decision. Two alternative models are proposed and their testable implications are derived and discussed. Both assume maximization of expected utility, but their assumptions about the expectations each player holds about the decisions of the remaining players are different. The effects of predccisional communication arc examined and several extensions of the basic paradigm are outlined. Although the interest of social psychologists in intergroup relations has been growing rapidly (Billi~, 1976; Brewer, 1979; Tajfel, 1982), the experimental research in this area is still sparse, especially when compared with the vast amount of research on interpersonal relations (Rabbie, 1982). The difficulty of simulating complex intergroup relations in the laboratory is one reason for the field's slow development (Gerard & Miller, 1967; Rabbie, 1982). Another and perhaps more important reason appears to be the lack of an integrated theory. Thus, Rabbie (1982) wrote: Although the literature offers a number of hypotheses about intergroup relations, these hypotheses do not form an integrated theory. They are usually stated at one particular level of analysis, they are sometimes contradictory, and their supporting evidence varies widely. (p. 124) The development of an integrated theory has been especially hindered by the traditional distinction between the interpersonal and intergroup levels of analysis. This distinction has characterized the theoretical study and experimental investigation of social conflicts and competitions for many years (Tajfel, 1982). Despite recent attempts to simultaneously investigate the interpersonal and intergroup aspects of social conflicts in small groups (Brewer & Kramcr, 1986; Kramer & Brewer, 1984), the literature shows little success in closing the gap between these two largely hypothetical levels of analysis. One possible way to narrow the gap is by designing and conducting systematic and theory-driven research of social situations involving small groups, in which social conflicts occur simultaneously at both levels of analysis. Extending the paradigm