Say's Law, J.S. Mill, and J.M. Keynes

Curated by Stephen Meardon, Editor

Some of the liveliest debates in the pages of the Journal of the History of Economic Thought over the past few years have concerned Say’s Law. They have addressed its foundation in Say’s writings and its construction by authors after Say, including both political economists and historians of economics. What is the meaning of the law—and is it what Say meant? How do historians of economics know what Say meant, anyway—and if what we know has ever been wrong, then how did we come to believe it? Did the formulations of Say’s Law by J.S. Mill and J.M. Keynes improve our understanding of Say and of the possibility of general gluts? Could they have improved our understanding of one but confounded the other?

This “virtual issue” of the Journal of the History of Economic Thought is a new experiment for the journal. It draws together in one collection, available online, the recent contributions to the foregoing questions in the dispersed print pages of JHET.

The impetus for a virtual issue was the publication of a discussion forum in the June 2018 issue of the journal. The forum comprised four contributions by five authors responding to an earlier JHET article: Roy Grieve’s 2016 “Keynes, Mill, and Say’s Law: The Legitimate Case Keynes Didn’t Make against J. S. Mill” (vol. 38, no. 3, pp. 329–349). Grieve had made a complex of arguments about the authors named in its title. According to Grieve, later and prominent readers of all three authors were correct to observe that, in a notable passage, Keynes misinterpreted Mill’s words as implying his allegiance to Say’s Law. And yet those readers were incorrect to conclude that Mill’s allegiance really lay elsewhere. It did not: although Keynes’s passage was wrong, he was right on other grounds to believe that Mill was, to his discredit, “deeply in thrall” to J.-B. Say.

So said Grieve. Some JHET contributors found what they considered links in his long interpretive chain, or weaknesses in the arguments of one another. First came a reply to Grieve by James Ahiakpor; following it, a rejoinder by Grieve; and then responses by Steven Kates and, finally, Alain Béraud and Guy Numa. The June 2018 discussion forum presented their contributions in that order.

But other contributions to JHET that were relevant to and even cited in the discussion did not appear in the forum itself. Such are the limitations of the print medium. One of those contributions, of course, is the 2016 article by Roy Grieve that provoked the discussion. Three more are Steven Kates’s 2015 article, “Mill’s Fourth Fundamental Proposition on Capital: A Paradox Explained” (vol. 37, no. 1, pp. 39-56); Roy Grieve’s 2017 letter in response, “Kates on Mill’s Fourth Proposition on Capital: Why All the Fuss?” (vol. 39, no. 2, pp. 271-272); and Alain Béraud and Guy Numa’s 2018 article, “Beyond Say’s Law: The Significance of J.-B. Say’s Monetary Views” (vol. 40, no. 2, pp. 217-241).

This virtual issue brings together all of the contributions to the discussion forum and these others, too. Perhaps this experiment can draw more attention to the contributions themselves and to JHET. The greater hope is that it can enliven even more our debates about the underlying questions, and thereby improve our answers.