Maximum principles in analytical economics.

The very name of my subject, economics, suggests economizing or maximizing. But Political Economy has gone a long way beyond home economics. Indeed, it is only in the last third of the century, within my own lifetime as a scholar, that economic theory has had many pretensions to being itself useful to the practical businessman or bureaucrat. I seem to recall that a great economist of the last generation, A. C. Pigou of Cambridge University, once asked the rhetorical question, " Who would ever think of employing an economist to run a brewery? " Well, today, under the guise of operational research and managerial economics, the fanciest of our economic tools are being utilized in enterprises both public and private. So at the very foundations of our subject maximization is involved. My old teacher, Joseph Schumpeter, went much farther. Instead of being content to say economics must borrow from logic and rational empirical enquiry, Schump-eter made the remarkable claim that man's ability to operate as a logical animal capable of systematic empirical induction was itself the direct outcome of the Darwinian struggle for survival. Just as man's thumb evolved in the struggle to make a living-to meet his economic problem-so did man's brain evolve in response to the economic problem. Coming forty years before the latest findings in ethology by Konrad Lorenz and Nikolaas Tinbergen, this is a rather remarkable insight. It would take me away from my present subject to more than mention the further view enunciated by Schumpeter [1] in launching the new subject of econometrics. Quantity, he said, is studied by the physicist or other natural scientist at a fairly late and sophisticated stage of the subject. Since a quantitative approach is, so to speak, at the discretion of the investigator, all the more credit to the followers of Galileo and Newton for taking the mathematical approach. But in economics, said Schumpeter, the very subject matter presents itself in quantitative form: take away the numerical magnitude of price or barter exchange-ratio and you have nothing left. Accounting does not benefit from arithmetic; it is arithmetic-and in its early stages, according to Schumpeter, arithmetic is accounting, just as geometry in its early stages is surveying. I must not leave you with the impression that analytical economics is