'Write Your Model Almost as You Would on Paper and Michel Will Take Care of the Rest!' Michel Juillard's Contribution to Macroeconomics in Historical Perspective

Abstract

This article assesses the contribution to macroeconomics of Michel Juillard, mostly known as the creator of the computer package Dynare. Dynare’s contribution to macroeconomics was twofold: one the one hand, Dynare has improved the tractability of DSGE models, that is, one’s ability to reliably solve, estimate, and simulate such models using a “reasonable” amount of computational resources; on the other hand, Dynare has improved the portability of DSGE models, that is, one’s ability to circulate and transfer models across people and institutions. As the creator of Dynare, Juillard has thus been a key figure in the history of the field, responsible for enhancing the dissemination and use of DSGE models across academia and policymaking institutions, by ensuring more tractability and portability of such models. But what does it mean “to create Dynare”—and, henceforth, what is exactly Juillard’s contribution to macroeconomics? Is this about just devising some algorithms, writing some computer code? In this article, we suggest that there is more to it. Adopting Elinor Olstrom’s perspective on commons, we argue that one should consider Dynare as a “digital commons”: that is, a shared digital resource, whose use and perennity (that is, the avoidance of the “tragedy” of its overuse, decline, and disappearance) is ensured by a set of governance rules (institutions) shared by the community of users. Henceforth, we argue, Juillard’s contribution to macroeconomics is threefold: it is, on the same footing, an intellectual contribution (devising algorithms, addressing a specific computational problem for a class of models), a “technical” one (writing code and developing a computer package), and an “institutional” one, consisting in creating the institutions ensuring the perennity of Dynare as a digital commons.

Keywords: history of macroeconomics, Dynare, Juillard (Michel), computerization of economics, digital commons