Modeling Covariate Transition for Efficient Estimation of Longitudinal Treatment Effects in Randomized Experiments
建模协变量转移以高效估计随机实验中的纵向处理效应
Naoki Chihara, Tatsushi Oka, Yasuko Matsubara, Yasushi Sakurai, Shota Yasui
AI总结 提出一种回归调整框架,通过建模协变量转移来估计随机实验中的纵向处理效应,并实现渐近正态性和半参数有效性。
详情
- Journal ref
- The 43rd International Conference on Machine Learning, 2026
- Comments
- Accepted by ICML'26
我们提出一个回归调整框架,用于在静态制度下估计随机实验中的纵向处理效应。虽然回归调整方法通过使用预处理协变量有助于随机实验中的方差减少,但它们通常只关注平均效应,从中我们无法获得关于效应何时出现以及持续多久的有价值见解。为了解决这个问题,我们考虑随时间变化的中间结果和事后协变量,并使用转移核表示这些动态轨迹。此外,我们建立了估计量的渐近正态性和半参数效率界,从而实现更强大的统计推断。使用日本某流媒体平台的A/B测试数据进行的模拟研究和实证分析显示了我们的方法的实际优势。
We present a regression-adjustment framework designed for the estimation of longitudinal treatment effects in randomized experiments under static regimes. While regression-adjustment methods are useful for variance reduction in randomized experiments by using pre-treatment covariates, they usually focus only on average effects, from which we cannot obtain valuable insights into when the effects appear and how long they continue. To address this issue, we consider intermediate outcomes and evolving post-treatment covariates over time, and we represent such dynamic trajectories using transition kernels. Furthermore, we establish the asymptotic normality and the semiparametric efficiency bound for our estimator, enabling more powerful statistical inference. Simulation studies and empirical analysis using A/B test data from a streaming platform in Japan show the practical advantages of our method.