Regularized Targeted Maximum Likelihood Estimation in Highly Adaptive Lasso Implied Working Models

Fuente: arXiv
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Autori principali: Li, Yi, Qiu, Sky, Wang, Zeyi, van der Laan, Mark
Natura: Preprint
Pubblicazione: 2025
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author Li, Yi
Qiu, Sky
Wang, Zeyi
van der Laan, Mark
author_facet Li, Yi
Qiu, Sky
Wang, Zeyi
van der Laan, Mark
contents We address the challenge of performing Targeted Maximum Likelihood Estimation (TMLE) after an initial Highly Adaptive Lasso (HAL) fit. Existing approaches that utilize the data-adaptive working model selected by HAL-such as the relaxed HAL update-can be simple and versatile but may become computationally unstable when the HAL basis expansions introduce collinearity. Undersmoothed HAL may fail to solve the efficient influence curve (EIC) at the desired level without overfitting, particularly in complex settings like survival-curve estimation. A full HAL-TMLE, which treats HAL as the initial estimator and then targets in the nonparametric or semiparametric model, typically demands costly iterative clever-covariate calculations in complex set-ups like survival analysis and longitudinal mediation analysis. To overcome these limitations, we propose two new HAL-TMLEs that operate within the finite-dimensional working model implied by HAL: Delta-method regHAL-TMLE and Projection-based regHAL-TMLE. We conduct extensive simulations to demonstrate the performance of our proposed methods.
format Preprint
id arxiv_https___arxiv_org_abs_2506_17214
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Regularized Targeted Maximum Likelihood Estimation in Highly Adaptive Lasso Implied Working Models
Li, Yi
Qiu, Sky
Wang, Zeyi
van der Laan, Mark
Methodology
We address the challenge of performing Targeted Maximum Likelihood Estimation (TMLE) after an initial Highly Adaptive Lasso (HAL) fit. Existing approaches that utilize the data-adaptive working model selected by HAL-such as the relaxed HAL update-can be simple and versatile but may become computationally unstable when the HAL basis expansions introduce collinearity. Undersmoothed HAL may fail to solve the efficient influence curve (EIC) at the desired level without overfitting, particularly in complex settings like survival-curve estimation. A full HAL-TMLE, which treats HAL as the initial estimator and then targets in the nonparametric or semiparametric model, typically demands costly iterative clever-covariate calculations in complex set-ups like survival analysis and longitudinal mediation analysis. To overcome these limitations, we propose two new HAL-TMLEs that operate within the finite-dimensional working model implied by HAL: Delta-method regHAL-TMLE and Projection-based regHAL-TMLE. We conduct extensive simulations to demonstrate the performance of our proposed methods.
title Regularized Targeted Maximum Likelihood Estimation in Highly Adaptive Lasso Implied Working Models
topic Methodology
url https://arxiv.org/abs/2506.17214