Dr. Clay studies international relations and comparative politics, focusing on the determinants of human rights practices, collective dissent, political violence, and economic development.  He is also highly interested in the international diffusion of local outcomes, as well as the institutions, organizations, and processes that facilitate such diffusion.  His research has been published in several outlets, such as the Journal of Politics, International Studies Quarterly, and the British Journal of Political Science.

Dr. Clay is also actively involved in the measurement of human rights practices.  He is the Co-Founder and Methodology Research & Design Lead for the Human Rights Measurement Initiative (HRMI), co-director of the archived CIRI Human Rights Data Project, and co-Principal Investigator on the Worker Rights in Law & Practice Data Project (WorkR) and the Sub-National Analysis of Repression Project (SNARP).

Dr. Clay teaches classes on human rights, political violence, international political economy, and international relations.  Through the GLOBIS Human Rights Research Lab, he also supervises the research of a large number of undergraduate and graduate students, who he teaches about the collection of quantitative human rights data and the conduct of scholarly research on the topics of human rights, political violence, and economic development.