British Journal of Political Science


Where Is the Tipping Point? Bilateral Trade and the Diffusion of Human Rights

Xun Cao, Brian Greenhill and Aseem Prakash *


Drawing on a panel of 136 countries over the period 1982–2004, we study a tipping point version of Vogel's ‘California Effect’ in the context of the diffusion of human rights practices. Because human rights practices are often deeply embedded in a society's customs and political institutions, we expect that a high level of pressure from the importing countries is needed to bring about changes in an exporting country's human rights records. We find strong empirical support for this threshold effect; provided that the average level of respect for human rights in importing countries is sufficiently high, trading relationships can operate as transmission belts for the diffusion of human rights practices from importing to exporting countries.

(Online publication July 09 2012)


*  Cao: Department of Political Science, Penn State University (email:; Greenhill: Department of Government, Dartmouth College; Prakash: Department of Political Science, University of Washington, Seattle. Previous versions of the article were presented at the annual conferences of the International Studies Association and the American Political Science Association. The authors thank Sarah Birch, Hugh Ward and the three reviewers for their comments. Replication data and R code as well as an online appendix containing more robustness checks are posted at: An appendix containing additional information is available online at: