Sequential Kernel Embedding for Mediated and Time-Varying Dose Response Curves

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Singh, Rahul, Xu, Liyuan, Gretton, Arthur
Format: Preprint
Published: 2021
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915198664704000
author Singh, Rahul
Xu, Liyuan
Gretton, Arthur
author_facet Singh, Rahul
Xu, Liyuan
Gretton, Arthur
contents We propose simple nonparametric estimators for mediated and time-varying dose response curves based on kernel ridge regression. By embedding Pearl's mediation formula and Robins' g-formula with kernels, we allow treatments, mediators, and covariates to be continuous in general spaces, and also allow for nonlinear treatment-confounder feedback. Our key innovation is a reproducing kernel Hilbert space technique called sequential kernel embedding, which we use to construct simple estimators that account for complex feedback. Our estimators preserve the generality of classic identification while also achieving nonasymptotic uniform rates. In nonlinear simulations with many covariates, we demonstrate strong performance. We estimate mediated and time-varying dose response curves of the US Job Corps, and clean data that may serve as a benchmark in future work. We extend our results to mediated and time-varying treatment effects and counterfactual distributions, verifying semiparametric efficiency and weak convergence.
format Preprint
id arxiv_https___arxiv_org_abs_2111_03950
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle Sequential Kernel Embedding for Mediated and Time-Varying Dose Response Curves
Singh, Rahul
Xu, Liyuan
Gretton, Arthur
Methodology
Machine Learning
Econometrics
We propose simple nonparametric estimators for mediated and time-varying dose response curves based on kernel ridge regression. By embedding Pearl's mediation formula and Robins' g-formula with kernels, we allow treatments, mediators, and covariates to be continuous in general spaces, and also allow for nonlinear treatment-confounder feedback. Our key innovation is a reproducing kernel Hilbert space technique called sequential kernel embedding, which we use to construct simple estimators that account for complex feedback. Our estimators preserve the generality of classic identification while also achieving nonasymptotic uniform rates. In nonlinear simulations with many covariates, we demonstrate strong performance. We estimate mediated and time-varying dose response curves of the US Job Corps, and clean data that may serve as a benchmark in future work. We extend our results to mediated and time-varying treatment effects and counterfactual distributions, verifying semiparametric efficiency and weak convergence.
title Sequential Kernel Embedding for Mediated and Time-Varying Dose Response Curves
topic Methodology
Machine Learning
Econometrics
url https://arxiv.org/abs/2111.03950