In many industrialised market economies collective bargaining has become so firmly established that it is sometimes regarded as being virtually synonymous with the prevailing system of industrial relations. Although it is perhaps the single most prevalent aspect of post-war industrial relations systems in advanced capitalist societies collective bargaining is in fact a multifaceted institution which, on an international basis, has diverse meanings and functions. The regularised patterns of union-management interaction, or the network of institutionalised bargained relationships, is referred to as the 'bargaining structure'. Industry-wide wage bargaining between national trade unions and employers' associations, whether conducted across an entire industry or, as in West Germany, more partially for the regional sub-divisions of an industry, has been the prevailing practice in most Western European countries. In the United States multi-employer or association bargaining at district or regional level was by no means unknown, primarily in industries exemplified once again by highly competitive product markets.