Most common property resource (CPR) collection in developing countries occurs in imperfect market environments, in which endogenous prices link the economic returns in non-resource activities (i.e., agriculture) with effort supplied to CPR collection. A model of an imperfectly integrated rural household demonstrates the theoretically ambiguous connection between agricultural productivity and resource collection. Using unique panel data from rural Mexico, we find evidence that households with higher agricultural efficiency supply less labor to CPR collection. Interventions that raise agricultural productivity thus may complement resource conservation efforts.