[Overview on the generalized propensity scoring estimator for continuous treatment].

Among kinds of methods for causal inference in observational studies, the propensity score (PS) method to control measured confounding is more widely used. PS method usually consists of two critical steps: first, estimating the propensity score, followed by calculating the causal parameters of interest by regression, weighting, matching, and stratification. Unlike the traditional dichotomous treatment, the generalized propensity scoring estimator used for continuous treatment has been proposed in recent years. Many methods have been developed to estimate the generalized propensity score or even estimate the balancing weight directly. This paper introduces the existing estimators from both the model-based and balance-based perspectives.