Lutz Leisering is Professor of Social Policy in the Faculty of Sociology, Bielefeld University, Germany, and founding member of the Institute for World Society Studies. He has published empirical, theoretical, and comparative studies of social policy in Europe and the global South, especially on old-age security, social assistance, global social policy, and the global diffusion of ideas. His publications include German Social Policy (5 volumes, Springer, 2013), The New Regulatory State: Regulating Pensions in Germany and the UK (Edited, Palgrave, 2011), and Time and Poverty in Western Welfare States: United Germany in Perspective (CUP, 1999).