Marcel Mauss published his essay The Gift (1925) in the context of debates about the European sovereign debt crises and the economic growth experienced by the colonies. This article traces the discursive associations between Mauss' anthropological concepts ("gift," "exchanges of prestations," and "generosity") and the reformist program of French socialists who pushed for an "altruistic" colonial policy in the interwar period. This article demonstrates that the three obligations which Mauss identified as the basis of a customary law of international economic relations (i.e. the duty to give, the duty to receive, and the duty to give back) served as key references in the French debate about the relationships between metropolises and colonies in the interwar period. Mauss made this relation between colonial policy and the ethnology of the gift explicit in his book, The Nation. Moving beyond Mauss' interwar writings, the article traces the genealogy of his later reflections to his involvement in prewar debates about chartered companies.