A Theory of Production in the Short Run
...the element of time, the source of many of the greatest difficulties in economics.--Alfred Marshall. The actual practice of economic science has been to first define capital in the concrete, and then, in the problems connected with it, to tacitly substitute again and again the abstract conception.... Even recent and acute discussions shift continually from one conception to the other, with results that baffle honest inquiry and make heresy plausible.--John Bates Clark.