Dramatic advances have recently marked the study of international joint ventures (IJVs). The progress has been mixed, however. Although several theoretical dimensions have been emphasized in the literature, researchers have not addressed certain crucial questions at the heart of the IJV relationship. Consequently, individually useful IJV studies have not coalesced into a collectively coherent body of work with an underlying theoretical structure. This weakness in theory development, I argue. may stem from the convergence of ''hard'' methodological approaches with ''soft'' behavioral variables. In proposing and justifying a research program toward deeper understanding of voluntary interfirm cooperation, I offer a theoretical framework for IJVs, develop a typology of theory-development approaches, and apply this framework and typology to demonstrate how a near-term shift in foci can accelerate rigorous IJV theory development.