Research on immigrant entrepreneurs initially attracted attention by collision with disciplinary orthodoxies. In the social sciences, extreme structuralism had long rejected any role for agency in small and medium business. Nonetheless, researchers into immigrant business required agency to explain their results. This agency they learned to call social and cultural capital. Already friendly to agency, business researchers speedily embraced the concepts of social and cultural capital as well as the insights of structuralism. The resulting theoretical synthesis took the name mixed embeddedness. Mixed embeddedness theory accepts input from both structure and agency but leaves their relative importance on a case-by-case basis. This dualistic structure/agency foundation opens and structures new avenues for research in a multiplicity of spun-off directions.