Published in 1999, this text is influenced by two sets of theories, namely regulation theories and theories on social citizenship. Regulation theories are mainly used as an overall guideline - a frame of reference - in the analysis of changed, unchanged and new types of integration and differentiation in working life and its social modes of regulations. The perspective on social citizenship is concentrated on participation in working life - what are the changes in working life (unemployment and non-standard employment) and what are the conditions and the outcome of social regulation? These questions are thematized in two articles and analyzed in chapter 7 which focuses on four welfare state models represented by Portugal, England, the Netherlands and Denmark. The book aims to contribute material on labour market segmentation and social policies to combat labour market marginalization in four countries studies representing typical European welfare state models.