With many couples separating every year, the question of how to determine the financial and property consequences of such separation has always been a problem area within family law. For married couples and cohabiting couples, should the principles be the same? Should the division of assets reflect the parties' own expectations or norms imposed by society? These are just two of the questions explored in this collection of essays. Recent cases in the UK's House of Lords have seen a willingness on the part of judges to seek out empirical studies which inform their deliberations, but if the law is to engage with empirical data then much more information is needed, both about the arrangements people make during their relationships and about the impact of the law when a relationship breaks down. Sharing Lives, Dividing Assets brings together leading academics - in the fields of law, economics, sociology, and psychology - to provide some of the missing empirical information. Part I of the book sets out the legal framework and identifies the importance of empirical studies for this area. Part II examines how couples - whether cohabitants or spouses - manage their money during their relationships. Part III then considers the impact that the law currently has on separating couples, examining how legal principles translate into reality and what their consequences are for the parties. Finally, Part IV considers the issue of legal rationality - it may be rational for the law to be shaped by patterns of behavior, but how far will individual couples allow their behavior to be shaped by the law?