Introduction

The path is strange that led Bertrand to the economists' Hall of Fame. As a mathematician, he made a single well-known incursion in our discipline, which was presumably designed as an attack against the use of mathematics in economics. This attack was accomplished in 1883 in a ten-page article of the Journal des Savants reviewing Walras's Mathematical Theory of Social Wealth, published in the same year, together with Cournot's Researches into the Mathematical Principles of the Theory of Wealth (1838), viewed as the main source of Walras's work. Each one of these two reviews contains one main objection, the first to Cournot's concept of duopolistic equilibrium, the second to Walras's analysis of the adjustment to equilibrium. These two objections became two independent sources of an astoundingly strong recognition (if we take into account the brevity of Bertrand's statements) by two communities working in two distinct fields that may be traced back to Cournot and Walras: industrial organization and general equilibrium theory, respectively.

As concerns industrial organization, with twenty lines criticizing three pages of one of the most important books in the history of economics, Bertrand attained with respect to the author of the Researches an almost symmetric position, assigned by supposedly opposite choices as regards the two main strategy variables that may be adopted by the competitors, namely prices and quantities.