This paper is a survey of recent theoretical work on the influence of group size, perceived effectiveness or noticeability of one's behavior on a group member's altruistic responses. Experiments on this problem are analyzed and evaluated, and problems for future research are outlined.
A few years ago I conducted an experiment to test certain propositions drawn from Olson's work (Olson, 1968) regarding group size and the provision of collective goods (Sweeney, 1973). The results of this experiment demonstrated that the free-rider phenomenon could be produced in the laboratory under controlled conditions and, in general, supported the proposition that the extent of the free-rider problem increases as group size increases.
However the experiment also raised certain questions with regard to the clarity of Olson's conceptualization of the problem and the inadequacy of his theory to explain certain anomalies which appeared in the data.
In this paper I undertake an examination of the concept size as it is used by Olson in The Logic of Collective Action and suggest that when Olson uses the term size, he means not actual size but perceived effectiveness and/or noticeability. Secondly, I discuss some of the experimental and theoretical research that has been done by social psychologists on the effects of group size. Here I put special emphasis on Steiner's conception of task demand models (Steiner, 1966) and the relevance certain of these models may have to the free-rider problem. Finally, I discuss some of the experimental work now being done on the subject of altruistic behavior and suggest that this work too may enlarge our understanding of the freerider problem.
I. OLSON'S CONCEPT OF SIZE
A key part of Olson's theory is that under certain conditions the size of a group will determine whether it will be able to reach its goals. But although Olson draws his implications about the effect of the size of a group on the question of whether the group will be able to provide itself Theory and Decision 4 (1974) 259-275.