Conformal Diffusion Models for Individual Treatment Effect Estimation and Inference

TL;DR

This paper introduces a novel conformal diffusion model approach for estimating individual treatment effects from observational data, providing accurate inference and confidence intervals with theoretical guarantees.

Contribution

It combines diffusion modeling, conformal inference, and local approximation techniques to improve individual treatment effect estimation and inference.

Findings

Achieves unbiased distribution estimation of potential outcomes.

Constructs informative confidence intervals with theoretical guarantees.

Demonstrates superior performance over existing methods in numerical studies.

Abstract

Estimating treatment effects from observational data is of central interest across numerous application domains. Individual treatment effect offers the most granular measure of treatment effect on an individual level, and is the most useful to facilitate personalized care. However, its estimation and inference remain underdeveloped due to several challenges. In this article, we propose a novel conformal diffusion model-based approach that addresses those intricate challenges. We integrate the highly flexible diffusion modeling, the model-free statistical inference paradigm of conformal inference, along with propensity score and covariate local approximation that tackle distributional shifts. We unbiasedly estimate the distributions of potential outcomes for individual treatment effect, construct an informative confidence interval, and establish rigorous theoretical guarantees. We demonstrate the competitive performance of the proposed method over existing solutions through extensive numerical studies.