Research on the labour market in the late twentieth century has tended to focus on perennial problems, such as unemployment and discrimination, or on the impact of changes in information and communication technologies ( Daniel, 1987; Howard, 1995), economic shocks, and major swings in government policy ( Boyer, 1989; Michie, 1992). This study has focused on the impact of social changes that produce less dramatic and sometimes invisible processes of gradual change and innovation in the labour market. The longterm impact of changes in sex-role attitudes, the feminization of the workforce, the prolongation of full-time education beyond adolescence and into early adulthood, the upskilling of the workforce, and the increased weight placed on autonomy and the exercise of skill by highly educated workers-- all these have been slow and continuous processes of social change rather than attention-grabbing sudden events. As Lieberson ( 1985: 183-5) points out, it is easy to underestimate their cumulative, long-term impact. The innovations they produce remain hidden in part because labour market statistics are churned out on a regular basis to largely predetermined formats, using fixed definitions and classifications. What we perceive is shaped by theoretical and common-sense preconceptions about what it is we are looking for. Academic discipline-based theory produces just as many blind spots as policy-oriented inquiries. Both perspectives are disabling in different ways.
A STRUCTURAL FEATURE OF THE LABOUR MARKET
Research on occupational segregation has so far been dominated by the search for an ideal single-number index which could be used to measure the pace of change over time in individual countries or groups of countries ( Hakim, 1993b, 1993c; Watts, 1993; J. Jacobs, 1989a; Siltanen, Jarman, and Blackburn, 1995). The new approach applied throughout this book was more fruitful than expected, revealing that occupational segregation is not just a useful theoretical concept but also a concrete, structural feature of the labour market. Labour market analyses using the new typology of male-dominated, female-dominated, and integrated or mixed occupations reveal fundamental differences between integrated occupations and segregated occupations, and