To this day, the so-called Arrow–Debreu model represents a trademark of rigorous economic research—be it as a benchmark for extending the model, for weakening its assumptions, for structuring data sets, or for providing alternative models. But who should earn the credit? Arrow or Debreu? This essay presents “the making of” Arrow’s and Debreu’s joint article of 1954 as documented in their extensive letter exchange between their first contact in February 1952 and submission in May 1953. I show, pivotally, that Arrow and Debreu did not share the same interest in their work, that they played different roles, and drew different lessons from it. Moreover, neither Arrow nor Debreu can be identified with the way the profession would later refer to the Arrow–Debreu model. To the contrary, both, in their own ways, sought to counter what others perceived as limitations when placing their hopes in the model.
Département des sciences économiques, Université du Québec à Montréal (UQAM), 315 St. Catherine St. East, Montréal H3C 3P8, Canada. I gratefully acknowledge the comments I received for previous versions at several conferences and workshops from Roger E. Backhouse, Vivienne Brown, Rodolphe Dos Santos Ferreira, M. Ali Khan, Steven G. Medema, and Joseph M. Ostroy. I thank the Bancroft Library, Berkeley, for their help in guiding me through the Debreu papers. I am particularly grateful to the most valuable correspondence and conversations with E. Roy Weintraub, on whose works the present account is built.