DAVID A. SNOW is Distinguished Professor Emeritus of Sociology at the University of California, Irvine, USA, where he also serves as the Co-Director of the Center for Citizen’s Peacebuilding. He has authored and edited several books and numerous articles and contributions to edited volumes on aspects of social movements and collective action, including A Primer on Social Movements (2010) and The Wiley Blackwell Companion To Social Movements (2e 2019, Wiley Blackwell).

DONATELLA DELLA PORTA is Professor of Political Science and Founding Dean of the Faculty of Political and Social Sciences at the Scuola Normale Superiore, Florence, Italy, where she also leads the Center on Social Movement Studies (Cosmos). Among her 90 books are Where Did the Revolution Go? (2017), Can Social Movements Save Democracy? (2020), Social Movements: An Introduction (3e 2020, Wiley Blackwell), and the most recent Contentious Politics in Emergency Critical Junctures (2022). She has been elected to the American Academy of Arts and Sciences in 2022.

DOUG McADAM is the Ray Lyman Wilbur Professor at Stanford University, USA. He is widely regarded as one of the pioneers of the political process model in social movement analysis. His books include Political Process and the Development of Black Insurgency (1982), Freedom Summer (1988), Dynamics of Contention (with Sid Tarrow and Charles Tilly, 2001) and, Deeply Divided: Racial Politics and Social Movements in Postwar America (2014). He was elected to the American Academy of Arts and Sciences in 2003.

BERT KLANDERMANS is Professor of Applied Social Psychology at Vrije Universiteit, Amsterdam, Netherlands. He has published extensively on the social psychology of protest and social movement participation. His authored and edited works include Social Psychology of Protest (1997), Extreme Right Activists in Europe (2005), Handbook of Social Movements Across Disciplines (2007), and The Future of Social Movement Research: Dynamics, Mechanisms, and Processes (2013).