International Organization

Research Article

Support for Free Trade: Self-Interest, Sociotropic Politics, and Out-Group Anxiety

Edward D. Mansfielda1 and Diana C. Mutza2

a1 Christopher H. Browne Center for International Politics, University of Pennsylvania, Philadelphia. E-mail:

a2 Institute for the Study of Citizens and Politics, University of Pennsylvania, Philadelphia. E-mail:


Although it is widely acknowledged that an understanding of mass attitudes about trade is crucial to the political economy of foreign commerce, only a handful of studies have addressed this topic. These studies have focused largely on testing two models, both of which emphasize that trade preferences are shaped by how trade affects an individual's income. The factor endowments or Heckscher-Ohlin model posits that these preferences are affected primarily by a person's skills. The specific factors or Ricardo-Viner model posits that trade preferences depend on the industry in which a person works. We find little support for either of these models using two representative national surveys of Americans. The only potential exception involves the effects of education. Initial tests indicate that educational attainment and support for open trade are directly related, which is often interpreted as support for the Heckscher-Ohlin model. However, further analysis reveals that education's effects are less representative of skill than of individuals' anxieties about involvement with out-groups in their own country and beyond. Furthermore, we find strong evidence that trade attitudes are guided less by material self-interest than by perceptions of how the U.S. economy as a whole is affected by trade.


Earlier versions of this article were presented at the 2006 annual meeting of the American Political Science Association, Philadelphia; seminars at the University of Chicago (Harris School), Emory University, Harvard University, and the University of Virginia; and a conference on Domestic Preferences and Foreign Economic Policy, held at Princeton University. We are grateful to Marc Busch, Jens Hainmueller, So Young Kim, Richard Valelly, the editors of International Organization, and two anonymous reviewers for helpful comments; to Rumi Morishima, Matthew Tubin, and Carmela Aquino for research assistance; and to the Christopher H. Browne Center for International Politics and the Institute for the Study of Citizens and Politics for financial assistance.

Note from the editors: Since one of the authors is an associate editor of this journal, the editors handled this article outside of the normal editorial management system and put in place special procedures to ensure rigorous, double-blind peer review.