Notes on Quasi-Convexity of the Cost Function
指出，在技术非凸的情况下，成本函数仍可满足拟凸性，并引入一个更弱的公理来保证这一性质，对生产理论中的对偶分析有参考价值。
Shephard (1970, 1974 a, 1974 b) and Jacobsen (1970, 1972) have shown that the cost function is convex if and only if the production technology of a firm is convex. Convexity of technology is a strong assumption, however, and in fact many problems of firms can be solved using the quasi-convex cost function only. In this note, we introduce a weaker axiom sufficient to make the cost function quasi-convex. Examples of the usefulness of quasi-convexity may be found in the field of dual production theory.