Bayesian causal forests with covariate balancing propensity score: a novel approach for heterogeneous treatment effects estimation
摘要
Bayesian causal forests (BCF) are a powerful method for estimating heterogeneous treatment effects (HTE) in the presence of confounding variables. However, the accuracy of BCF critically depends on the correct estimation of propensity scores (PS); misspecified PS can lead to biased estimates of the treatment effect. To address this limitation, we propose BCF with covariate balancing propensity scores (BCF-CBPS), which integrates covariate balancing directly into the PS estimation step. By replacing conventional PS with CBPS, our approach improves covariate balance, enabling BCF to more accurately estimate true treatment effect heterogeneity. Extensive Monte Carlo simulations and real-world applications demonstrate that BCF-CBPS achieves higher precision and robustness compared to standard BCF and other machine learning methods for HTE estimation. These results highlight the effectiveness of combining covariate balancing with the BCF model for reliable estimation of treatment effects in complex observational studies.