What sustains slavery, and why at critical junctures – the fall of the Roman Empire, the early modern expansion of plantation agriculture, the later phases of the industrial revolution, the totalitarian regimes of the 1930s – has it often expanded or contracted so rapidly? Why have owners and rulers sometimes been united, but sometimes violently divided, over the choice between free and servile labor? An extremely simple dual-equilibrium picture offers (a) insights into how rapid transitions can occur and (b) specific hypotheses about the parameter shifts that govern such changes and divisions. Extending earlier work by Domar and Lagerlöf, I establish the likelihood of an “inverted-U” relationship between forced labor and labor scarcity: both very scarce and very abundant labor inhibit slavery, while intermediate endowments, and particularly an intermediate ratio of land to labor, can easily make slavery the more profitable alternative. Internal divisions over slavery are likely to be most intense as a society approaches either of these “tipping points.” The most striking example, explored fleetingly here, is the U.S. Civil War.
Ronald Rogowski, a Professor of Political Science at UCLA, specializes in comparative politics and political economy. His book Commerce and Coalitions explores how international trade shapes domestic political coalitions. In 1999, the American Political Science Association honored him by organizing a roundtable discussion to commemorate the tenth anniversary of its publication. His recent work considers how the design of electoral systems affects a nation's economic policies. He has also investigated globalization, capital mobility, and the sources of price differentials across national boundaries. Rogowski teaches an undergraduate introduction to comparative politics and a graduate course on the external sources of domestic politics. Professor Rogowski served as the Chair of the Political Science Department during a period of growing national prominence. He has been a Fellow at the Center for Advanced Study in the Behavioral Sciences.