My research focuses on social networks: how and why people are socially connected to each other and the consequences of those connections. Within this broad area, I am especially interested in demographic processes, specifically how population dynamics shape family, kinship, and social networks and how those networks in turn affect health and other population processes. I have given special attention to migration and the network ties that migrants retain to origin areas after moving as well as the new ties they form in different destinations. I am also very interested in using social networks as a basis for sampling populations that are otherwise difficult to survey, including migrants, those at high risk of sexually transmitted or blood-borne infections, and opioid users. In this line of research, I am working on new ways to use and improve network based sampling methods, especially respondent-driven sampling.