The study of federal political systems, particularly parliamentary or representative federal political systems, such as those in the United States, Canada, or India involves complexities that do not exist in unitary states such as Great Britain or France. In the first place, there are three or more institutional levels in such systems, each of which has its own arena in which political struggles take place. Second, the balance of power among the levels in federal systems varies in different systems and in the same system at different times. Third, the study of the extraparliamentary organizations, such as political parties, and of social movements, also becomes a more complex task since it cannot be assumed that a political party or social movement with the same name is the same sort of formation in New York and Mississippi or in Uttar Pradesh and Tamil Nadu. Moreover, in federal systems with a high degree of regional cultural diversity, each federal unit in the country may have a distinctive configuration of extraconstitutional political formations and social forces. This is certainly the case in India, the most culturally diverse of all existing federal parliamentary systems in the world today. Fourth, politics in federal systems takes place between levels as well as within levels, again in far more complex ways than in unitary systems.