‘Mixed economy’ we take to refer to the complex institutional arrangements of resource allocation in modern society; mixed economy policy analysis is concerned with a positive administrative theory for steering resource allocative processes. The present article reviews some basic definitions, dimensions and models of mixed economy and discusses several formal reasons for why so little progress has been made towards an administrative theory of mixed economy. A policy implementation perspective is used to provide an alternative conception of mixed economy allocative processes and a method for researching them. Data from a current research project on mixed economy strategies for ‘Helping Small Firms Grow’ are used to illustrate arguments in the article.