Introduction: Lucas’s enduring impact on macroeconomic thinking

Fifty years have passed since the Journal of Economic Theory published Robert E. Lucas’s seminal paper (1972) on expectations and the neutrality of money. The influence this contribution exerted on how we today think about macroeconomic theory and methodology proved to be so profound and far-reaching that it is still one of the core works of the macroeconomic corpus. Improvements in science, however, are seldom linear and cumulative, new developments may thus surpass once powerful and well-performing theories by showing that their old truths are not general and eternal but partial and temporary only. Not even a Nobel prize is a guarantee of a theory being a fixed star in the sky of science. The 50th anniversary of the neutrality paper promises to be a good opportunity for reflecting on its impact, and ask how the profession assesses this pathbreaking contribution in the light of the developments of the past few decades. In May 1995, a few months before the early-October press release announcing Lucas’s Nobel prize in economics, Rao Aiyagari set up a meeting to celebrate the 25th anniversary. Some of the authors in this special issue also attended that conference. With this special issue we aspire to do the same: to revisit, to evaluate, to celebrate and to appreciate. Hopefully, this symposium, just as the 25th anniversary conference, will promote theoretical and methodological thinking and equally prove to be a nice surprise to a hero of ‘the golden age of macroeconomics’ as Blanchard (2000, p. 1379) termed the 1940–1970s. The papers in this issue are organized into two sections. After the introductory paper that summarizes the strikingly rapid intellectual and technical progress which led Lucas to the neutrality paper, the first section contains three articles by three authors from three subsequent periods of Lucas’s career. These articles assess Lucas’s achievements in areas such as university teaching, model building or econometric practice. All these articles are meant to combine personal, occasionally even subjective, reflections on Lucas’s lifework with theoretically and methodologically anchored comprehensive evaluations. The personal touch is most saliently present in Tom Sargent’s account who tells the so far untold story of his friendship with Lucas and how they joined forces in the 1960–1970s in their battle against the then conventional Keynesian way of macroeconomic modeling. Max Gillman, Lucas’s former graduate student at the University of Chicago, embeds his recollections of Lucas’s professorship into describing the various ways the neutrality paper still shapes macroeconomic thinking. In a similar vein, Harald Uhlig, a current faculty member at the Department of Economics of the University of Chicago, offers an insider look into the Chicago milieu and explains how and in what ways it still preserves Lucas’s fingerprints. These articles also include personal recollections and will be valuable resources for historians and methodologists who would like to look beyond the body of published texts. So apart from intending to give new impetus to the Lucas reception, these papers also have the promise of fueling historical assessments of modern macroeconomics in general and the Chicago school in particular.