Rachel A. Epstein is a professor of international relations, with a focus on both international political economy and international security. Her research spans topics from financial crises, the politics of foreign bank ownership, and financial reform to the enlargement of the European Union and the North Atlantic Treaty Organization and those organizations' effects on target states. With a particular focus on East Central Europe, Epstein's research has examined democratic erosion in the region, Russia's invasion of Ukraine, and the developmental prospects of post-communist states for catching up in the European and global economies.

Epstein has also served as a lead principal investigator on a number of collaborative grants, including from the Carnegie Corporation of New York on responsible policy engagement. This work explores the ethical dilemmas that researchers confront as they share their scholarly findings with policymakers or become involved in policy processes directly. Epstein and her colleagues' research in this area alerts scholars to the possibility that conflicts of interest, concealed political commitments, and threats to ethical redlines may emerge in unexpected ways in the research-to-policy interface. Findings from the team also infuse the curriculum at the Korbel School and beyond. It is imperative that researchers and practitioners alike consider the ethical dimensions of traditional international relations theorizing and the ways in which methodological and research design choices elevate some interests above others.

Professor Epstein has had a number of appointments beyond the Korbel School as well as administrative positions within the School. She has served as a Jean Monnet post-doctoral fellow, a Transatlantic research fellow, and as a Senior Fellow at the Robert Schuman Centre for Advanced Studies at the European University Institute in Florence, Italy. She was also a Senior Fellow at the Otto Suhr Institute of Political Science at Free University in Berlin. From 2014 to 2018, Epstein was co-editor of the Review of International Political Economy. Professor Epstein was Associate Dean for Faculty Affairs and Research from 2018 to 2021 and then Senior Associate Dean of the Korbel School until 2024.