The ability to predict how national electricity industries will respond to the challenges of competition and the demand for sustainability requires a good understanding of the nature of technological systems and a workable theory of technology choice. So far, two distinct theoretical perspectives, the economic and socio-political concepts of technological systems, have competed for dominance in policy analysis and policy making. This paper is a comparative study of the way in which the electricity industries of Denmark and France responded to a series of challenges beginning with the 1973 oil crisis and continuing through the present push to liberalise electricity markets. Focussing on the forces that directed technological change in these two nations, I examine the relative importance of economic and socio-political factors. My analysis indicates that socio-political factors which, together, can be described as political traditions have shaped technology choice. The Danish and French electricity industries have pursued several objectives in addition to economic efficiency. This has limited the function of free markets. Thus, they should be understood as political structures whose most important characteristic is the distribution of power. In this context, the economic perspective represents a normative demand for the re-arrangement of political values. Technological choice which radically departs from the status quo implies a significant redistribution of political power and is, therefore, very difficult.