The central question in this essay is simple yet important: Why are some working classes more organized than others? This phenomenon has since World War II shown increased variation among Western capitalist countries (von Beyme 1980; Wallerstein 1989). The latest figures show that unionization among these countries ranges from below 15% in France to 86% in Sweden (see Table 2.1). Among industrialized Western states hardly any other political variables of this kind vary to such an extent. In this essay I will equate degree of unionization with workingclass strength. It can of course be argued that working-class strength is also dependent on other variables such as party organization and cultural homogeneity. But following Marxist theory, unionization may be seen as the primary organization form of the working class and can thus be considered a basis for other forms of working-class strength, such as political and cultural organization (Olofsson 1979; Offe and Wiesenthal 1980).

The importance of the level of working-class organizational strength stems, inter alia, from the established positive correlation between union strength and the development of welfare-state policies. One can say that, with few exceptions, the stronger is the organization of the working class, the more developed the welfare state (Korpi 1983; Shalev 1983a, b; Amenta and Skocpol 1986; Noble 1988). But, critically, this correlation does not in itself show how the causal link between social policies and working-class formation operates.