Abstract: Severe degree heterogeneity is a universal phenomenon in large social networks. However, the degree parameters are largely nuisance to our major interest, and their effects can be carefully removed with proper statistical strategies. In the first part of the talk, I will take the mixed-membership estimation as an example and present several useful ideas for dealing with degree heterogeneity.   We assume the network has K perceivable communities. Each node is associated with a K-dimensional “membership” vector whose...

Abstract: In many social science experiments, subjects often interact with each other and as a result one unit's treatment influences the outcome of another unit. Over the last decade, a significant progress has been made towards causal inference in the presence of such interference between units. However, much of the literature has assumed perfect compliance with treatment assignment. In this paper, we establish the nonparametric identification of the complier average direct and spillover effects in two-stage randomized experiments with interference and noncompliance....

Abstract: Many empirical studies throughout the social and biomedical sciences focus only on very narrow outcomes such as income, or a single specific disease state, or a measure of positive affect. Human well-being or flourishing, however, consists in a much broader range of states and outcomes, certainly including mental and physical health, but also encompassing happiness and life satisfaction, meaning and purpose, character and virtue, and close social relationships. The empirical literature from longitudinal, experimental, and quasiexperimental studies is reviewed...

Joscha Legewie is an Assistant Professor of Sociology at Harvard University.