This article reviews the main theoretical perspectives on the development of welfare states that more or less explicitly conceptualize the interests of particular social groups in retirement-income systems. The main capital–labour cleavage between the interests of employers and labour movements in such systems is juxtaposed. Then, several intra-class cleavages are presented. These conflicts influence and are reinforced by fragmented pension systems, in particular the difference between blue-collar and white-collar workers as well as that between the private and public sectors. Weaker labour-market groups, in particular the unemployed, and gender issues in retirement-income systems are discussed. The article also critically reviews often-voiced generational conflicts
