Nonparametric Estimation of Mediation Effects with A General Treatment

Fuente: arXiv
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Main Authors: Huang, Lukang, Huang, Wei, Linton, Oliver, Zhang, Zheng
Format: Preprint
Published: 2022
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_version_ 1866913204236451840
author Huang, Lukang
Huang, Wei
Linton, Oliver
Zhang, Zheng
author_facet Huang, Lukang
Huang, Wei
Linton, Oliver
Zhang, Zheng
contents To investigate causal mechanisms, causal mediation analysis decomposes the total treatment effect into the natural direct and indirect effects. This paper examines the estimation of the direct and indirect effects in a general treatment effect model, where the treatment can be binary, multi-valued, continuous, or a mixture. We propose generalized weighting estimators with weights estimated by solving an expanding set of equations. Under some sufficient conditions, we show that the proposed estimators are consistent and asymptotically normal. Specifically, when the treatment is discrete, the proposed estimators attain the semiparametric efficiency bounds. Meanwhile, when the treatment is continuous, the convergence rates of the proposed estimators are slower than $N^{-1/2}$; however, they are still more efficient than that constructed from the true weighting function. A simulation study reveals that our estimators exhibit a satisfactory finite-sample performance, while an application shows their practical value
format Preprint
id arxiv_https___arxiv_org_abs_2210_08228
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Nonparametric Estimation of Mediation Effects with A General Treatment
Huang, Lukang
Huang, Wei
Linton, Oliver
Zhang, Zheng
Statistics Theory
Methodology
To investigate causal mechanisms, causal mediation analysis decomposes the total treatment effect into the natural direct and indirect effects. This paper examines the estimation of the direct and indirect effects in a general treatment effect model, where the treatment can be binary, multi-valued, continuous, or a mixture. We propose generalized weighting estimators with weights estimated by solving an expanding set of equations. Under some sufficient conditions, we show that the proposed estimators are consistent and asymptotically normal. Specifically, when the treatment is discrete, the proposed estimators attain the semiparametric efficiency bounds. Meanwhile, when the treatment is continuous, the convergence rates of the proposed estimators are slower than $N^{-1/2}$; however, they are still more efficient than that constructed from the true weighting function. A simulation study reveals that our estimators exhibit a satisfactory finite-sample performance, while an application shows their practical value
title Nonparametric Estimation of Mediation Effects with A General Treatment
topic Statistics Theory
Methodology
url https://arxiv.org/abs/2210.08228