"Let me begin by answering your question concerning the existence of a crisis in economic theory. I think the answer is that economics is now recovering from a long period of decline that was caused by the transition it attempted to make from microeconomics to macroeconomics. Keynes is clearly responsible for this change although he was by no means alone. But he has contributed, perhaps unintentionally, more than anybody else to the spread of aggregative theorizing, which is the essence of macroeconomics. I personally believe that only microeconomics really explains anything, but it is of necessity limited in its power of explanation. And, precisely because of these limitations in its explanatory capacity, economists decided to construct a new system which they thought to be more scientific: macroeconomics. This attempt, however, was based on erroneous hypothesis and has been a complete failure. I must confess that for the past thirty years I have not been interested in most of the subjects which have occupied the minds of the majority of economists: macroeconomics, welfare economics, employment theory, input-output analysis, the theory of growth, etc."