Laws of intestate succession determine how the estate of a person who dies without a will is distributed. Researchers have struggled with the question of how to infer the donative intent of persons who die intestate. Based on an empirical study of unmarried committed partners, we compare the usefulness of two methods of social research for informing intestacy law: will studies and interviews with living persons about their preferences for estate distribution. The results indicate that for some groups of unmarried committed partners, will studies may not adequately reflect the extent to which intestate decedents wish their partner to share in their estate. In addition, the results demonstrate a close correspondence between respondents' actual wills, when they had them, and their distributive preferences on hypothetical scenarios. These findings are discussed as they relate to an examination of which sources of social scientific evidence are most useful in informing the law of intestacy.