Business Cycle Theory Restated

In light of his theory of interest, Mises now clarified the relationship between interest and changes in the quantity of money. The Austrian (Misesian) theory of the business cycle asserts that intertemporal misallocations result from inflation-induced reductions of the interest rate. But what was the precise meaning of “reduction”? Mises did not mean to assert that simple changes of the interest rate would induce a business cycle. The fact that today's interest is lower than yesterday's does not by itself mean that a misallocation has occurred.

In his Theory of Money and Credit, Mises had based his analysis on the Wicksellian distinction between the natural rate of interest and the money rate. But this distinction was untenable in light of Mises's work on economic calculation and on the non-neutrality of money. There is no such thing as a natural rate of interest, defined as the rate of interest that would prevail in a barter economy. And even if there were such a “natural” rate of interest, it would still be irrelevant for the analysis of a monetary economy. Money is not just a veil over a barter economy. It affects all economic relations. Prices, incomes, allocation, and social positions in an economy using money are completely different from what they would be in a society with no common medium of exchange. And so the interest rate in a monetary economy is necessarily different from what it would have been in the same economy if the market participants had decided to forgo the benefits of money. Even if one could hypothetically compare “natural” and money interest rates—which is not the case—it would not follow that intertemporal misallocations would ensue whenever the “natural” rate was higher than the money rate.

In Nationalökonomie, Mises gave a new exposition of his business cycle theory. He came up with a new benchmark to identify pernicious reductions of the monetary interest rate. The relevant benchmark was no longer the Wicksellian natural rate that would exist if the economy were a barter economy. It was rather the monetary interest rate that would exist in the absence of credit expansion.³⁹

Any increase in the supply of credit on the market will reduce the interest rate, but if the increase comes from printing paper money or banknotes (rather than from savings) then the artificially lower interest rate falsifies the entrepreneurial profit calculus. In light of the decreased interest rate, a greater number of business projects appear to be profitable and are launched. But the material factors of production necessary for the physical completion of the greater number of projects do not exist. Credit expansion does not mean expansion of the real factor endowment of the economy; it merely means expansion of the money supply through the credit market. It follows that it is physically impossible to sustain the new structure of production that resulted from the credit expansion. The boom must eventually end in a bust.⁴⁰