European integration has not only changed the career opportunities for politicians, it has expanded them. This volume is devoted to the study of political career patterns, focusing primarily on parliamentary careers in selected countries across Europe. Additionally, the US is included as a long-standing system with multi-level politics. These contributions represent the first systematic investigation into level-hopping practices in Europe. While trying to explain the logic of moves across political levels, special attention is given to the impact of institutional reforms. The results indicate that the traditional model of career mobility, with the national and supra-national levels as the apex of a career, is still of importance in most countries, yet a clear trend towards multi-directional political careers is found.