The purpose of this article is to propose a draft for an analytical frame for analyzing regional integration consisting of federalism theory and neo-functionalism. It starts out discussing the concept of regional integration setting up a stagiest model for categorizing it.Then follows an analysis of federalism theory and neo-functionalism. One argument of this article is to understand federalism theory as a regional integration theory. Another is to
look at federalism theory as complementary to neo-functionalism when trying to explain regional integration. Federalism theory, in an extended Riker-McKayian way, is able to explain the cases of ‘big bang’ integration (USA, Australia, Canada), but not an ‘organic’ integration process. Neo-functionalism, on the other hand, is not able to explain this relatively fast form of integration, but it is – in its new version - able to analyze and explain the ‘organic’ or slow integration processes like those happening in Europe, and other places in the world. Thus the two should be seen as complementary and they are, jointly, a
frame catching most processes of regional integration.