In this paper we aim to explain the differences observed in the career patterns of national and regional MPs in a multi-level layered out system as Spanish. There are different patterns of parliamentary careers between territorial levels and we explore different explanations, such as the party (left Vs. right, statewide Vs. non-statewide), territorial identity (strong-weak), previous political office experience, previous appointed office experience, party position, magnitude of electoral district, gross regional product or un-employment rate. We use a model to try to explain these differences in career patterns in and between different political levels. That will allow us to build up in the differentiation of political arenas in a multi-level system.
