His current research focuses on the political culture within Europe and the US. The main emphasis is placed on the interaction between macro level characteristics and individual attitudes and behavior. Here, a core research question is whether political attitudes are influenced stronger by modernization processes or by institutional settings. Other research topics are voting behavior, social inequality, mobility, and methods of empirical research. Most of his research is done in an international comparative view. For this purpose survey data are used and related to country characteristics by multilevel analyses.