Economic policy making is discussed from three different angles: the political economy of actual policy making (“what policy does do”), the analysis of policy instruments for given ends (“what policy could do”), and the debate on policy goals and their legitimization (“what policy ought to do”). Center stage in the evolutionary perspective is new, positive and normative knowledge which is unfolding during the policy making process and in its aftermath. It is argued that this implies regularities and constraints which extend and modify the comparative-static interpretations of public choice theory, economic policy making theory, and social philosophy.