This paper presents an empirical test of the Marxian claim that the social relations of production have meaningful economic consequences. It presents econometric evidence that in the region studied (the antebellum U.S. South) the social relations of production had an effect on the interregional pattern of production that achieved both statistical significance and economic importance. However, the evidence also indicates that the social relations or production are only one, and not always the most important, of the many determinants of the interregional pattern of production. Copyright 1994 by Oxford University Press.