Time on the Cross: The Economics of American Negro Slavery (1974) is a book by the economists Robert Fogel and Stanley L. Engerman. Fogel and Engerman argued that slavery was an economically rational institution and that the economic exploitation of slaves was not as catastrophic as presumed, because there were financial incentives for slaveholders to maintain a basic level of material support for those they held as property. The book was reprinted in 1995 at its twentieth anniversary. The book contradicts the long-standing notion that slavery was economically backwards, underdeveloped the South, and was on the path to extinction before the Civil War broke out. It attracted widespread attention in the media and generated heated controversy and criticism for its methodology and conclusions.