“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

In this article, we document Michel Juillard's contribution to macroeconomics. Best known as the creator of the computer package Dynare, Juillard's impact extends far beyond software development. We trace his training and career from his first encounter with computers in high school through his ongoing work on Dynare. His contribution to macroeconomics, we argue, is threefold: intellectual (devising algorithms and addressing specific computational problems for a class of models), technical (writing code and developing a computer package), and institutional (establishing and maintaining the governance structures that ensure Dynare's sustainability as a digital commons). Juillard's career highlights broader questions about adapting Ostrom's framework to digital commons development, the principles that govern software development, and the place computational economics should occupy in the history of macroeconomics.