“…Our paper is related to several lines of research. Bugni et al (2018); Bugni, Canay, and Shaikh (2019); Hu and Hu (2012); Ma, Hu, and Zhang (2015); Ma, Qin, Li, and Hu (2020); Olivares (2021); Shao and Yu (2013); Shao, Yu, and Zhong (2010); Zhang and Zheng (2020); Ye (2018); Ye and Shao (2020) studied inference of either ATEs or QTEs under CARs without considering additional covariates. Bloniarz, Liu, Zhang, Sekhon, and Yu (2016); Fogarty (2018); Lin (2013); Lu (2016); Lei and Ding (2021); Li and Ding (2020); Liu, Tu, and Ma (2020); Liu and Yang (2020); Negi and Wooldridge (2020); Ye, Yi, and Shao (2021); Zhao and Ding (2021) studied the estimation and inference of ATEs using a variety of regression regression methods under various randomization.…”