Friedrich A. Hayek, “The Mythology of Capital” (1936) — Summary

Hayek’s “The Mythology of Capital” is a single-author theoretical journal article. Its scope is a polemical reconstruction of capital theory against Frank H. Knight’s attack on the Austrian “period of investment.” In six sections Hayek states Knight’s position, clears away misconceptions about Austrian time analysis, answers Knight’s examples, argues that Knight cannot explain how capital scarcity limits output, examines the zero-interest case, and closes on perfect foresight.

Hayek’s central thesis is double-edged. He accepts that Böhm-Bawerk’s single “average period of production” is an over-simple abstraction, but insists that Knight’s alternative—a self-maintaining capital fund—is worse. Capital is not a permanent substance behind changing things; it is a structure of heterogeneous, perishable goods whose replacement must be economically explained.

The very concept of capital arises out of the fact that, where nonpermanent resources are used in production, provision for replacement of the resources used up in production must be made, if the same income is to be enjoyed continually, and that in consequence part of the gross produce has to be devoted to their reproduction.

This is the article’s anti-mythological center. Hayek shifts attention from “capital” as a quantity to capital goods as dated arrangements of resources. What matters is not the time needed to produce a named commodity, nor a measurable social average, but the periods for which particular factors are invested. More “capitalistic” production may mean transferring factors from shorter to longer uses, producing more durable goods, or changing the economy’s mix of processes.

The theory looks forward, not back.

That aphorism marks a key conceptual move. Hayek rejects attempts to ground capital theory in past “original factors.” Relevant calculation concerns prospective intervals between present investment and future return. His “investment function” is meant to describe future services and waiting, not to reduce them to a single period.

Knight’s agricultural example, in which additional capital supposedly raises output without lengthening a cycle, fails because it fixes attention on the crop rather than on the resources diverted into it. If saving is genuinely required, some factor must be moved from a use yielding earlier income to one yielding later income.

Evidently this example in no way proves that a case is conceivable where additional capital is used without having the effect of lengthening the investment period of some factor.

The constructive core of the essay is Hayek’s account of maintenance and replacement. A stock of capital goods is not equivalent to one predetermined “subsistence fund.” It can be combined with other resources to yield many possible future streams of consumers’ goods. The economic datum is therefore not a homogeneous fund, but a range of alternative time-shaped income streams.

It should be clear that an analysis of this effect of the existence of capital goods on the direction of the investment of current resources is possible only in terms of the alternative time structures of production which are technically possible with a given equipment.

This also explains Hayek’s attack on Knight’s zero-interest claim. Even if the marginal productivity of further waiting fell to zero, capital goods and consumers’ goods need not become free goods, because their reproduction would still require scarce factors. The issue is not whether “capital” has a mystical productivity, but how scarce resources are allocated across time.

In the final section, Hayek argues that Knight’s appeal to perfect foresight narrows his theory almost to irrelevance. If everything had always been foreseen, production plans would already be fixed and ordinary capital problems would disappear. Real economies, however, continually face unforeseen change, and capital theory must explain adaptation, maintenance, and replacement under such change.

Economic problems of any sort, and in particular the problem of how to use a given stock of capital goods most profitably, arise only when it is a question of adjusting the available means to any new situation.

The article’s relevance lies in preserving the Austrian insight that capital scarcity is a limit on waiting while discarding both the average-period simplification and the fiction of a homogeneous fund. Hayek’s core move is methodological: dynamic capital theory must begin from heterogeneous goods, dated services, and the alternative future income streams they make possible.