Easy-to-Implement Two-Way Effect Decomposition for Any Outcome Variable with Endogenous Mediator
内生中介下适用于任意结果变量的简便直接与间接效应分解
Given a binary treatment D and a binary mediator M, mediation analysis decomposes the total effect of D on an outcome Y into the direct and indirect effects. Typically, both D and M are assumed to be exogenous, but this paper allows M to be endogenous while maintaining the exogeneity of D, which holds certainly if D is randomized. The endogeneity problem of M is then overcome using a binary instrumental variable Z. We derive a nonparametric "causal reduced form (CRF)" for Y…