The Hayek/Knight Capital Controversy: The Irrelevance of Roundaboutness,or Purging Processes in Time?
回顾了哈耶克与奈特关于资本理论的经典争论，指出生产周期概念缺乏明确意义，且与投资数量无关，对理解资本本质无理论价值。
Neither changes in the durability of goods nor changes in their construction period... exerts an identifiable effect on a definable “period of production ” in society as a whole. Moreover, they are similarly unconnected with quantity of investment, and quantity of investment is likewise unconnected with any production period. Correspondences in this field are limited and accidental, without theoretical significance for the nature and rôle of capital. It is extremely difficult to give any intelligible meaning to a “period of production, ” and it certainly has no meaning of the sort assumed in the Böhm-Bawerk–Hayek theory of capital. —Frank Knight, “Professor Hayek and the Theory of Investment ” (1935) [Knight’s permanent, homogeneous fund of capital and J. B. Clark’s true capital] are just so many evasions of the real problem of explaining how the existence of a given stock of capital limits the possibility of current investment. Without such an analysis they are just so many empty words, harmful as the basis of the noxious mythology of capital which by creating the fiction of a non-existing entity leads to statements which refer to nothing in the real world.