Vent for surplus or productivity breakthrough? The Ghanaian cocoa take-off, c. 1890–1936

type="main"> Through a case study of cocoa-farming in Ghana, this article takes up the long-running but recently neglected debate about the ‘cash crop revolution’ in tropical Africa during the early colonial period. It focuses on the supply side, to test the much criticized but never superseded ‘vent-for-surplus’ interpretation of the export expansion as a substitution of labour for leisure. The article argues that while the model captured certain features of the case, such as the application of labour to underused land, its defining claim about labour is without empirical foundation. Rather, the evidence points to a reallocation of resources from existing market activities towards the adoption of an exotic crop, entailing a shift towards a new, qualitatively different and more profitable kind of production function. This innovation is best understood in the context of the long-term search of African producers for ways of realizing the economic potential of their resource of relatively abundant land, while ameliorating the constraints which the environment put upon its use.