Ruud is Research Director at the WZB Berlin Social Science Center and Professor of Sociology and Migration Research at Humboldt University Berlin. His research focuses on migration and integration, religious fundamentalism and extremism, and majority and minority rights. His most recent books deal with the crisis of the Islamic world (Das verfallene Haus des Islam; CH Beck, 2020; also translated into Dutch, Danish and Norwegian); the tension between majority and minority rights (Majorities, Minorities, and the Future of Nationhood, with Liav Orgad, Cambridge University Press, 2022); and European refugee policies (Die Asyl-Lotterie; CH Beck 2023, also translated into Dutch and Danish).