There Is No Consistency in Keynes's Use of the Term “Rate of Interest”; Keynes Also Fails to Adhere to His Own Theory of Interest (Liquidity Preference and Quantity of Money)

Let us consider first Keynes's failure to adhere to fixed meanings for his terms.

Keynes at times uses the rate of interest to mean a rate of discount, measuring the premium on present goods over future goods. This is implied in his initial definition of the marginal efficiency of capital, to which later reference is made on page 135 of this book. It is, moreover, made explicit by Keynes on page 93 of his book, where he says that, as an approximation, we can identify the rate of time-discounting, i.e., the ratio of exchange between present goods and future goods, with the rate of interest. Later, however, Keynes gives us a radically different theory of interest. He makes the rate of interest depend on liquidity preference and the quantity of money. And he holds that interest is not paid for the purpose of inducing men to save but for the purpose of inducing men not to hoard. He holds that if money is made sufficiently abundant so that it can satiate liquidity preference, it will pull down, not merely the short time rate of interest or the short time money rates, but also the whole complex of interest rates, long and short. The whole complex of interest rates (with a given liquidity preference scale) can be governed, and is governed, in his system, by the abundance or scarcity of money. Interest becomes a phenomenon of money par excellence. Strangely enough, however, we find Keynes playing with the notion of commodity rates of interest, or “own rates of interest,” the rate between future wheat and present wheat, and designating this rate as the “wheat rate of interest.” Every commodity can have its own rate of interest in terms of itself, and Keynes says that there is no reason why the wheat rate of interest should be equal to the copper rate of interest, because the relation between the spot and future contracts as quoted in the markets is notoriously different for different commodities. The reader will find whatever he pleases in Keynes about the rates of interest, though his formal theory is the doctrine that the quantity of money, taken in conjunction with liquidity preference, governs the rate of interest.

But Keynes does not adhere long to his own theory of interest. In the same volume, 29 pages later, he has abandoned it. After saying, on pages 167-168, that the supply of money in relation to liquidity preference will govern the whole complex of interest rates, long and short, on page 197 he criticizes the Federal Reserve banks for their open market policy, 1933-1934, on the ground that they purchased only short term securities, the effect of which “may, of course, be mainly confined to the very short term rate of interest and have little reaction on the much more important long term rates of interest.” And he calls upon the central banks to regulate all rates of interest by having fixed rates at which they will buy obligations of differing maturities, long and short.

There is no consistency in Keynes's use of the term “rate of interest” in this volume.

--Benjamin M. Anderson, “Digression on Keynes,” in The Critics of Keynesian Economics, ed. Henry Hazlitt (Irvington-on-Hudson, NY: Foundation for Economic Education, 1995), 199-200.