All over Europe, the social conditions under which couples become parents in the early twenty-first century differ markedly from those of their parents’ generation. Unlike earlier cohorts, today’s women and men tend to have quite similar life experiences and skills when they form a couple and decide to start a family. Yet, research shows that couples still appear to be giving up gender equal divisions of labour in favour of more traditional family arrangements upon entering parenthood. This chapter presents the theoretical and analytical framework used in this book to assess the ‘why’ and ‘how’ of these transitions in eight European countries. It explicitly locates couples’ beliefs and negotiations in the wider context of national institutions, such as national family policies, employment protection, care provision and gender ideologies about motherhood and fatherhood. In particular, the chapter introduces the notion of policy-culture gaps as a tool to analyse varying degrees of fit between national family policies and key dimensions of dominant gender culture.