by Friedrich A. Hayek

American Economic Review. XXXV, No. 4. pp. 519-30. American Economic Association

copyright：

The text of this edition is copyright ©: 1945, American Economic Review, XXXV, No. 4; September, 1945, pp. 519-30. Reprinted with permission.

source：https://www.econlib.org/library/Essays/hykKnw.html

part I

What is the problem we wish to solve when we try to construct a rational economic order? On certain familiar assumptions the answer is simple enough. If we possess all the relevant information, if we can start out from a given system of preferences, and if we command complete knowledge of available means, the problem which remains is purely one of logic. That is, the answer to the question of what is the best use of the available means is implicit in our assumptions. The conditions which the solution of this optimum problem must satisfy have been fully worked out and can be stated best in mathematical form: put at their briefest, they are that the marginal rates of substitution between any two commodities or factors must be the same in all their different uses.

当我们想要构建一个合理的经济秩序时，是为了决什么问题呢？在几个熟悉的假设基础上，答案显而易见：如果我们拥有所有相关的信息，如果我们可以从任一种给定的偏好系统出发，并且，如果我们我们掌握了关于可用手段的全部知识，那么剩下的问题就纯粹是一个逻辑问题——我们的假设中隐含了这样一个问题——什么是现有手段的最佳利用方式？已经有人对这个最优化问题的解必须满足的条件进行了充分研究，这一条件用数学形式表示最为恰当。简单来说，这个条件就是：

任何两种商品或要素之间的边际替代效率在它们的所有用途中必须是相同的。

This, however, is emphatically not the economic problem which society faces. And the economic calculus which we have developed to solve this logical problem, though an important step toward the solution of the economic problem of society, does not yet provide an answer to it. The reason for this is that the “data” from which the economic calculus starts are never for the whole society “given” to a single mind which could work out the implications and can never be so given.