Her research interests include the global sex trade, human trafficking, migration, and women’s labor in Latin America and the Caribbean. In 2004, Brennan authored the book, What’s Love Got to Do with It?: Transnational Desires and Sex Tourism in the Dominican Republic and was awarded an American Association of University Women fellowship for the same academic year. Brennan received an M.A. in International Relations from Johns Hopkins SAIS, and both a MPhil and Ph.D. from Yale University.