My contribution to economics has been to urge the inclusion in our analysis of features of the economic system so obvious that they have tended to be overlooked. Nonetheless, once included in the analysis, they will, as I believe, bring about a complete change in the structure of economic theory, at least in what is called price theory or microeconomics. What I have done is to show the importance for the working of the economic system of what may be termed the institutional structure of production. I shall explain why, in my view, these features of the economic system were ignored and why their recognition will lead to a change in the way we analyze the working of the economic system and in the way we think about economic policy, changes which are already beginning to occur. I will also address the empirical work that needs to be done if this transformation in our approach is to increase our understanding.