Transfer Learning of CATE with Kernel Ridge Regression

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Kim, Seok-Jin, Liu, Hongjie, Liu, Molei, Wang, Kaizheng
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866910942884790272
author Kim, Seok-Jin
Liu, Hongjie
Liu, Molei
Wang, Kaizheng
author_facet Kim, Seok-Jin
Liu, Hongjie
Liu, Molei
Wang, Kaizheng
contents The proliferation of data has sparked significant interest in leveraging findings from one study to estimate treatment effects in a different target population without direct outcome observations. However, the transfer learning process is frequently hindered by substantial covariate shift and limited overlap between (i) the source and target populations, as well as (ii) the treatment and control groups within the source. We propose a novel method for overlap-adaptive transfer learning of conditional average treatment effect (CATE) using kernel ridge regression (KRR). Our approach involves partitioning the labeled source data into two subsets. The first one is used to train candidate CATE models based on regression adjustment and pseudo-outcomes. An optimal model is then selected using the second subset and unlabeled target data, employing another pseudo-outcome-based strategy. We provide a theoretical justification for our method through sharp non-asymptotic MSE bounds, highlighting its adaptivity to both weak overlaps and the complexity of CATE function. Extensive numerical studies confirm that our method achieves superior finite-sample efficiency and adaptability. We conclude by demonstrating the effectiveness of our approach using a 401(k) eligibility dataset.
format Preprint
id arxiv_https___arxiv_org_abs_2502_11331
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Transfer Learning of CATE with Kernel Ridge Regression
Kim, Seok-Jin
Liu, Hongjie
Liu, Molei
Wang, Kaizheng
Methodology
Machine Learning
The proliferation of data has sparked significant interest in leveraging findings from one study to estimate treatment effects in a different target population without direct outcome observations. However, the transfer learning process is frequently hindered by substantial covariate shift and limited overlap between (i) the source and target populations, as well as (ii) the treatment and control groups within the source. We propose a novel method for overlap-adaptive transfer learning of conditional average treatment effect (CATE) using kernel ridge regression (KRR). Our approach involves partitioning the labeled source data into two subsets. The first one is used to train candidate CATE models based on regression adjustment and pseudo-outcomes. An optimal model is then selected using the second subset and unlabeled target data, employing another pseudo-outcome-based strategy. We provide a theoretical justification for our method through sharp non-asymptotic MSE bounds, highlighting its adaptivity to both weak overlaps and the complexity of CATE function. Extensive numerical studies confirm that our method achieves superior finite-sample efficiency and adaptability. We conclude by demonstrating the effectiveness of our approach using a 401(k) eligibility dataset.
title Transfer Learning of CATE with Kernel Ridge Regression
topic Methodology
Machine Learning
url https://arxiv.org/abs/2502.11331