Unmarried opposite-sex cohabitation ('cohabitation') is rapidly increasing in Britain and is expected to double from its 1996 level by 2021. A quarter of children are now born to unmarried cohabiting parents. This is not just an important change in the way we live in modern Britain; for cohabitation has also become a political and theoretical marker. Some commentators see it as evidence of the rise of selfish individualism and the breakdown of the family, others - probably in an equally extreme way - see cohabitation as the best partnering form for 'post-modern intimacy' and the 'pure relationship'. Politically, 'stable' families are seen as crucial, especially by a British government which sees social morality as vital for a sustainable society. But how far can and should governments intervene and regulate? At the same time, and partly reflecting this, the law still retains important distinctions in the way it treats cohabiting and married families. Should the law be changed to reflect a changing social reality, or should it - can it - be used to direct these changes? Using findiings from their recent Nuffield Foundation funded study, combining a nationally representative analysis of cohabitation and marriage with in-depth qualitative data about what cohabitants do and believe, the book explores public attitudes to cohabitation and marriage and the 'common law marriage myth' (the false belief that cohabitants have the same or similar legal rights as married couples). It also provides an analysis of who cohabits, who marries and why and investigates legal attitudes and beliefs about 'cohabitation and common law marriage' and concludes by considering attitudes to and options for legal reform in the light of the research findings.