The Logic of Collective Action

Olson attacked the assumption, common in political science and sociology at the time, that individuals with a shared interest will act together to advance it. His argument is that a rational individual in a large group will not contribute to a collective good, because the individual bears the full cost of contributing while receiving only a tiny fraction of the benefit, and because the good will be available whether or not the individual contributes.

The argument produces a size prediction. Small groups organise successfully because each member's share of the benefit is large enough to justify the cost, and because members can observe each other. Very small groups exhibit what Olson called the exploitation of the great by the small, where the largest member provides the good and the others free-ride on it. Large groups fail to organise unless they use selective incentives, meaning private benefits withheld from non-contributors, or coercion.

The explanatory payoff is that lobbies representing concentrated producers routinely defeat dispersed consumers and taxpayers, not because producers are more numerous or more virtuous, but because they can organise and the others cannot. Olson used union closed shops, professional associations and farm groups as evidence, and he later extended the framework to national economic decline in The Rise and Decline of Nations.

The theory has been challenged by evidence that people contribute to public goods more than the model predicts, by experimental economics on conditional cooperation, and by Elinor Ostrom's work showing that communities govern common resources through institutions Olson did not anticipate. The core insight about concentrated versus dispersed interests remains standard.