The model of integration initially adopted by the European Community Treaty, a common market, is a form of market integration. The core of the common market is a series of 'individual economic freedoms' which limit Member State's ability to intervene in, and thus impede, this transaction economy. Member States' ability to restrict free movement of goods is limited by a number of provisions. The European Communities attempt to integrate developed economies of a mixed, capitalist variety. Modern economic constitutions, however, are heavily influenced by political attempts to pursue material objectives as opposed to the 'formal rationality'. As a consequence of political efforts to assign particular economic results to specific groups, formal law becomes 'materialised'. Treaty, by establishing a common market and progressively approximating the economic policies of the Member States seeks to unite national markets in a single market having the characteristics of a domestic market.