  I establish primitive conditions for unconfoundedness in a coherent model
that features heterogeneous treatment effects, spillovers,
selection-on-observables, and network formation. I identify average partial
effects under minimal exchangeability conditions. If social interactions are
also anonymous, I derive a three-dimensional network propensity score,
characterize its support conditions, relate it to recent work on network
pseudo-metrics, and study extensions. I propose a two-step semiparametric
estimator for a random coefficients model which is consistent and
asymptotically normal as the number and size of the networks grows. I apply my
estimator to a political participation intervention Uganda and a microfinance
application in India.
