““After the war, when the problem of deficient effective demand seemed to have faded into the background, a fresh question came to the fore — long-run development. The change arose partly from the internal evolution of economics as an academic subject. The solution of one problem opens up the next; once Keynes’ short-period theory had been established, in which investment plays the key role, it was evidently necessary to discuss the consequences of the accumulation of capital that investment brings about. [p. 92]””
