Egoistic theories of collective action assume that such actions arise in the course of individuals pursuing their own interests. Communal organizations present a challenging puzzle for this view, as many of these organizations achieve very high levels of cooperation without formal incentives, such as wages or fines. This dissertation begins with the problem of solidarity in communes and provides a theory of informal social control, explaining group solidarity as a product of elementary social exchanges between members. It models aspects of organizational structure that condition and coordinate these exchanges, leading to compliance, malfeasance, or factionalism in simulated groups. On a macro-level, it will integrate dynamic models of organizational ecology with recent experimental work examining "exit options" in exchange relations. The marriage of these two frameworks will situate the micro-model of group processes in a macro-model of population ecology, as linked by choices of simulated agents to join and exit groups. To test the fit of these formal models, predicted outcomes will be compared against observed dissolutions of over 2,000 communal organizations, founded between 1609 and 1997. While the database includes records of over 1,200 communes, this project will expand and validate the existing database through visits to several historical archives and a survey of contemporary communes. In addition to testing a two-tiered theory of organizational solidarity, this project will provide an unprecedented record of structural trends and population dynamics for communal organizations over a span of nearly four centuries.
