Lies, Damn Lies and OLS Weights Part 5

I think this will be the last one! Maybe!

“In many empirical studies in social sciences, causal effects are estimated through linear regression [which has an] exogeneity assumption [that] combines unconfoundedness with functional form and constant treatment effect assumptions that are quite strong, and arguably unnecessary.'' -- Imbens and Rubin (2015)

I think this will be the last in the series…