Friedrich A. Hayek, “The Uses of ‘Gresham’s Law’ as an Illustration of ‘Historical Theory’” — Summary

This file is a short single-author theoretical essay, later printed as a chapter, in which Hayek uses Gresham’s Law to clarify how economic theory can serve historical explanation. Its scope is deliberately narrow: it does not offer a general history of money, but a methodological demonstration. Hayek’s target is the historian’s reliance on an empirical maxim—“bad money drives out good”—without specifying the conditions under which that maxim is true.

Hayek begins by distinguishing a familiar historical rule from a usable theoretical proposition. The saying is ancient, he notes, and only accidentally associated with Gresham. As an unsupported empirical slogan, however, it explains very little.

And as a mere empirical rule it is practically valueless.

The essay’s central thesis is that historical explanation requires theory not as abstract ornament, but as a way of identifying the relevant causal conditions. Properly formulated, Gresham’s Law becomes an instance of “compositive social theory”: it explains how individual uses of money, under given institutional and market conditions, can produce a collective change in circulation.

If Gresham’s Law is properly stated with the conditions in which it applies, it will appear that as a proposition of compositive social theory it can indeed provide a useful tool of historical explanation.

Hayek then reconstructs the law. The decisive condition is not simply that one money is “bad” and the other “good,” but that the same two monies have equal value in some uses and unequal value in others. Legal-tender rules may make worn and full-weight coins equivalent for paying domestic debts, while foreign trade or industrial use values the metal content differently.

The essential condition is that there must be two kinds of money which are of equivalent value for some purposes and of different value for others.

This conditional formulation allows Hayek to explain why “good” coins need not immediately disappear. New and worn coins may circulate together for long periods if inflows replace outflows. The change appears only when external or industrial uses begin to draw full-weight coins away faster than they are replenished.

The two kinds of coin may for a long time circulate side by side and be accepted as equivalent not only internally but even externally if there is a net influx of money into the country concerned.

Against the idea that the disappearance of specie must follow from new public recognition that one form of money is undervalued, Hayek argues that no new knowledge is required. Foreign merchants and goldsmiths may always have preferred full-weight coins; what changes is the surrounding monetary balance.

No change of this sort need have become newly known.

The historian’s task, therefore, is not to search for a sudden discovery about coin quality, but for a change in the conditions governing flows of money and its alternative uses. Theory directs attention to a fall in the internal value of coin relative to its foreign or industrial value, and away from misleading explanations such as clipping or wear alone.

What theory will tell him is that he must look for some cause which led to a fall of the internal value of both good and bad coins relative to their value in foreign commerce and in industrial uses.

The essay closes by applying this methodological lesson to historical episodes such as the German “Kipper and Wipper” crisis and the English re-coinage of 1696. Hayek’s point is not that historians need elaborate formal economics, but that even elementary theory prevents false causal narratives. Gresham’s Law, correctly stated, illustrates both the usefulness and the limits of theory: it does not replace archival inquiry, but tells the historian what kind of evidence would matter.

Like most of the theory which is likely to be useful to the historian, it is only very simple and elementary theory which is required; and the usual conception of Gresham’s Law is a very good illustration of how theory may and how it will not help the historian.