2017 年 30 巻 1 号 p. 27-44
In this study, we propose a new estimation procedure for incomplete survival data caused by nonignorable nonresponses or missing censoring indicators. It is widely known that if there is any nonignorable missingness or censoring indicators cannot be fully observed, the results from survival analysis such as the Kaplan-Meier estimator or the Cox proportional hazard model may be biased. However, it sometimes occurs that nonignorable missingness cannot be specified and that the censoring indicators are never or partially observed. We propose a Bayesian generalized method of moments (GMM) approach that utilizes population-level information to identify true survival time and estimates parameters. We apply the proposed model to analyze purchase duration in marketing using purchase history data.