Adam Smith had one overwhelmingly important triumph: he put into the center of economics the systematic analysis of the behavior of individuals pursuing their self-interest under conditions of competition.

Even before I came to Chicago, I had gotten interested in the existence of dispersion of prices under conditions which economic theory said would yield a single price.

Theories are not rejected by cirsumstantial evidence: it takes a theory to beat a theory.

Why, when the economist gives advice to his society, is he so often cooly ignored? He never ceases to preach free trade, and protectionism is growing in the United States. He deplores the perverse effects of minimum wage laws, and the legal minimum is regularly raised each 3 or 5 years. He brands usury laws as a medieval superstition, but no state hurries to repeal its law.

In the 1950s, I proposed the survivor method of determining the efficient sizes of enterprises, and worked on delivered price systems, vertical integration, and similar topics.

That subject has lost its one time appeal to economists as our science has become more abstract, but my interest has even grown more intense as the questions raised by the sociology of science became more prominent.

I started working and publishing in price theory by 1938.