Common property as an egalitarian share contract

Common property is an endogenous institution and modeled as a joint wealth maximizing egalitarian share contract among an exclusive group of resource owners. The conditions are derived in which common property generates greater wealth than private property. A distinction is made between contracts in which group members share final output and contracts in which groups only share access to a commonly owned resource. In both cases homogeneity in production by members is shown to be efficient. Several case studies of common ownership are presented as support of the model.