Université de Fribourg

Direct and indirect effects under sample selection and outcome attrition

Huber, Martin ; Solovyeva, Anna

(Working Papers SES ; 496)

This paper considers the evaluation of direct and indirect treatment effects, also known as mediation analysis, when outcomes are only observed for a subpopulation due to sample selection or outcome attrition. For identification, we combine sequential conditional independence assumptions on the assignment of the treatment and the mediator, i.e. the variable through which the indirect effect...

Université de Fribourg

Nonparametric estimation of natural direct and indirect effects based on inverse probability weighting

Hsu, Yu-Chin ; Huber, Martin ; Lai, Tsung Chih

(Working Papers SES ; 482)

Using a sequential conditional independence assumption, this paper discusses fully nonparametric estimation of natural direct and indirect causal effects in causal mediation analysis based on inverse probability weighting. We propose estimators of the average indirect effect of a binary treatment, which operates through intermediate variables (or mediators) on the causal path between the...