“…To be sure, our study is certainly not the first such effort, and, indeed, a sizeable Bayesian literature has evolved for the estimation of treatment-response models with observational data. 2 Early efforts in this regard primarily focused on the Markov chain Monte Carlo (MCMC) implementation (e.g., Poirier, 1997 andChib andHamilton, 2000) and included some discussion of recovering individual-level treatment impacts within a potential outcomes framework. 3 More recent work has focused on problems associated with weak instruments generally, has discussed priors that yield posteriors similar to sampling distributions for the two-stage least squares (2SLS) and limited information maximum likelihood (LIML) estimators (e.g., Kleibergen and Zivot, 2003), has introduced a non-parametric modeling of outcomes via a Dirichlet process prior (Conley et al, 2008), and has obtained new results associated with the seminal Angrist and Krueger (1991) study (e.g., Hoogerheide et al, 2007).…”