Bernard Enjolras is Research Professor and Director of the Center for Research on Civil Society and Voluntary Sector in NorwayLester M. Salamon is a Professor at the Johns Hopkins University, USA and Director of the Johns Hopkins Center for Civil Society StudiesKarl Henrik Sivesind is Research Professor at the Institute for Social Research, NorwayAnnette Zimmer is Professor of Social Policy and Comparative Politics and Lead Researcher for Third Sector Impact work at Münster University, Germany