The core problem of economic sociology is the way in which rational-individualistic-economic action is related to collective social commitments, norms and structures. This is explored from a variety of perspectives, employing both traditionally sociological and economic approaches. Particular attention is paid to analyses of the four main social structures and constructs in which economic action occurs: markets, contracts, “networks,” and firms. The program includes general and conceptual as well as empirical approaches, and also covers policy-oriented material. As one of its central concerns, the program focuses on the institutional conditions of a virtuous development of advanced industrial economies.