Harvey Leibenstein has written a major new book in microeconomic theory. It is a sophisticated reorientation of microtheory that breaks away from the conventional, highly refined neoclassical theory, which in turn is in the direct line of descent from Adam Smith's The Wealth of Nations (1776). The author accomplishes this feat by introducing modern psychological concepts to microtheory, by using individuals instead of collections of individuals as his basic units of study, and by suggesting that relating the theory to the concept of effort (an X-efficiency factor) will provide the...