krebscycle

If I am right in supposing it to be comparatively easy to make capital-goods so abundant that the marginal efficiency of capital is zero, this may be the most sensible way of gradually getting rid of many of the objectionable features of capitalism. For a little reflection will show what enormous social changes would result from a gradual disappearance of a rate of return on accumulated wealth. A man would still be free to accumulate his earned income with a view to spending it at a later date. But his accumulation would not grow. He would simply be in the position of Pope’s father, who, when he retired from business, carried a chest of guineas with him to his villa at Twickenham and met his household expenses from it as required.[cite]

Here’s a radical proposition: to arrange the economy so it’s very difficult to make money from investments. Actually what Keynes is mostly discussing is interest income and what economists call rentiers – people who accumulate money from their assets without doing additional work. People could accumulate wealth via work and smart active investment, but capital would be available at such a low cost that the huge industry we have of banks and wealth managers and trust funds and hedge funds would not be sustainable.

Though the rentier would disappear, there would still be room, nevertheless, for enterprise and skill in the estimation of prospective yields about which opinions could differ. For the above relates primarily to the pure rate of interest apart from any allowance for risk and the like, and not to the gross yield of assets including the return in respect of risk. Thus unless the pure rate of interest were to be held at a negative figure, there would still be a positive yield to skilled investment in individual assets having a doubtful prospective yield. Provided there was some measurable unwillingness to undertake risk, there would also be a positive net yield from the aggregate of such assets over a period of time. But it is not unlikely that, in such circumstances, the eagerness to obtain a yield from doubtful investments might be such that they would show in the aggregate a negative net yield.

Keynes is here making an argument for an economic system where interest rates are effectively zero for reasonably safe loans so that just having money would not be a means of making more money.