The papers collected here deal with various topics in economic theory, ranging from preference and consumption, duality and production, equilibrium, capital, and growth, to the theory of social overhead capital. They all have a common theme: to try to formulate the working of economic forces in a capitalist economy in terms of mathematical models and to explore their static, dynamic, and welfare implications.

Most of the papers were published during the 1960s and a few in the early 1970s. Economic theory since then has made significant progress, both in the refinement and elaboration of analytical methods and in the enlargement of the scope of economic inquiries. In particular, institutional and social aspects of the contemporary economic systems have been explicitly incorporated into the formal framework of the economic theory, and their implications for the mechanism of economic processes have been fully explored. However, the analytical methods developed in the papers and the theoretical implications derived thereby still seem to retain value, particularly in tracing the origin of some of the contemporary works in economic theory.

This volume represents work done while I was affiliated with Stanford University, the University of California at Berkeley, and the University of Chicago. During this period, I was extremely fortunate in being able to work with Professor Kenneth J. Arrow, whose intellect influenced almost all the work I was then doing. I should like to take this opportunity to acknowledge my intellectual and personal indebtedness to him.