The Clémentel moment: the reform of 1918 and the beginnings of regional economic planning in France.

This article examines the 1918 reform by Étienne Clémentel, then French ministre du Commerce, which reorganized France's 149 chambers of commerce into seventeen regional groupings to promote economic modernization and regional development. The reform reflected a broader shift in French economic policy toward corporatism and pluralism, encouraging intermediary corporate bodies—such as chambers of commerce and producer associations—to act as partners between the state and private interests in managing the economy. Drawing on pre-war regionalist debates and wartime economic planning, the article details how these regional groupings played key roles in infrastructure projects, technical education, and energy development, particularly in regions like Lorraine and Auvergne. Clémentel's approach laid institutional groundwork for post-World War II regional economic planning and contributed to the gradual decentralization and pluralistic management of the French economy.