The purpose of this study is to present the principles, strategy and operation of the social market economy, based on legal, political and economic considerations. The first social market economy, West Germany – followed by Austria, the Netherlands, as well as other countries in Northern and Western Europe –, mustered a positive overall performance from the post-World War II years to the early 1970s. Since then, however, we have been witnessing the erosion, distortion and decline of efficiency of the social market economy. There are four main issues to be addressed: (i) What are the main theoretical and conceptual, ‘eternal’ elements of the social market economy? (ii) What economic policy was built on this theoretical foundation and why did the system work well in Western Europe after World War II? (iii) What factors eroded this system? (iv) Can social market economy be renewed in the second decade of the 21st century and, if it can, what are the preconditions of it? In my analysis, I highlight some key areas: EU policies, Lisbon Agenda and Europe 2020 strategy, growth, financial disequilibria and competitiveness, innovation and employment, the relation of state and market.