His main research areas are in the area of comparative public policy research with a focus on the welfare state and the politics of welfare state reforms, fiscal policies as well as law and order policies for which he has received funding from the German Research Council (DFG). His recent work has been published by the Journal of Public Policy (on the myth that successful fiscal adjustments mean cutting the welfare state), the Journal of European Public Policy (on the validity of replacement rate data) or Politics & Policy (on Political Strategy).