Université de Fribourg

Bounds on direct and indirect effects under treatment/mediator endogeneity and outcome attrition

Huber, Martin ; Lafférs, Lukáš

(Working Papers SES ; 514)

Causal mediation analysis aims at disentangling a treatment effect into an indirect mechanism operating through an intermediate outcome or mediator, as well as the direct effect of the treatment on the outcome of interest. However, the evaluation of direct and indirect effects is frequently complicated by non-ignorable selection into the treatment and/or mediator, even after controlling for...

Université de Fribourg

Direct and indirect effects based on changes-in-changes

Huber, Martin ; Schelker, Mark ; Strittmatter, Anthony

(Working Papers SES ; 508)

We propose a novel approach for causal mediation analysis based on changes-in- changes assumptions restricting unobserved heterogeneity over time. This allows disentangling the causal effect of a binary treatment on a continuous outcome into an indirect effect operating through a binary intermediate variable (called mediator) and a direct effect running via other causal mechanisms. We...

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

The causalweight package for causal inference in R

Bodory, Hugo ; Huber, Martin

(Working Papers SES ; 493)

We describe R package “causalweight” for causal inference based on inverse probability weighting (IPW). The “causalweight” package offers a range of semiparametric methods for treatment or impact evaluation and mediation analysis, which incorporates intermediate outcomes for investigating causal mechanisms. Depending on the method, identification relies on selection on observables ...

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...

Université de Fribourg

A framework for separating individual treatment effects from spillover, interaction, and general equilibrium effects

Huber, Martin ; Steinmayr, Andreas

(Working Papers SES ; 481)

This paper suggests a causal framework for disentangling individual level treatment effects and interference effects, i.e., general equilibrium, spillover, or interaction effects related to treatment distribution. Thus, the framework allows for a relaxation of the Stable Unit Treatment Value Assumption (SUTVA), which assumes away any form of treatment-dependent interference between study...

Université de Fribourg

Direct and indirect effects of training vouchers for the unemployed

Huber, Martin ; Lechner, Michael ; Strittmatter, Anthony

(Working Papers SES ; 456)

This paper evaluates the effect of a voucher award system for assignment into vocational training on the employment outcomes of unemployed voucher recipients in Germany, along with the causal mechanisms through which it operates. It assesses the direct effect of voucher assignment net of actual redemption, which may be driven by preference shaping/learning about (possibilities of) human capital...