Treatment Effect Estimation for Exponential Family Outcomes using Neural Networks with Targeted Regularization
Jiahong Li, Zeqin Yang, Jiayi Dan, Jixing Xu, Zhichao Zou, Peng Zhen, Jiecheng Guo
TL;DR
This work tackles confounding bias in observational treatment effect estimation for exponential-family outcomes by developing an end-to-end neural network estimator for the Average Dose Canonical Function (ADCF). It derives the von Mises expansion to identify the first-order bias and constructs a doubly robust estimator, then generalizes targeted regularization to exponential families, with theoretical convergence guarantees. The proposed framework is instantiated with explicit forms for Bernoulli and Poisson outcomes and implemented via a two-head NN predicting $\mu(\mathbf{x},a)$ and $\pi(a|\mathbf{x})$, augmented by a distribution-scale regularization term that mitigates bias. Empirical results on synthetic and semi-synthetic data (News and TCGA) show state-of-the-art performance across binary and continuous treatment regimes, highlighting the method’s applicability to real-world outcomes beyond Gaussian assumptions.
Abstract
Neural Networks (NNs) have became a natural choice for treatment effect estimation due to their strong approximation capabilities. Nevertheless, how to design NN-based estimators with desirable properties, such as low bias and doubly robustness, still remains a significant challenge. A common approach to address this is targeted regularization, which modifies the objective function of NNs. However, existing works on targeted regularization are limited to Gaussian-distributed outcomes, significantly restricting their applicability in real-world scenarios. In this work, we aim to bridge this blank by extending this framework to the boarder exponential family outcomes. Specifically, we first derive the von-Mises expansion of the Average Dose function of Canonical Functions (ADCF), which inspires us how to construct a doubly robust estimator with good properties. Based on this, we develop a NN-based estimator for ADCF by generalizing functional targeted regularization to exponential families, and provide the corresponding theoretical convergence rate. Extensive experimental results demonstrate the effectiveness of our proposed model.
