Politics is about collective decision-making. Aside from political parties it is interest groups that represent crucial collective actors in contemporary democracies. Whenever binding decisions are taken for the sake of the common good you will find both special interest groups and public interest groups actively engaged. How are interest groups created, how do they develop, and how do interest groups exert influence on public policy? In this course we will explore the theoretical framework for interest group politics. Also, we will take a look at empirical studies that pinpoint tactics of lobbying in different political settings. Special emphasis will be put on the United States and Europe compared. In case studies students will analyze crucial realms and items of lobbying. The course will be held in English.