Cost sharing and cost shifting mechanisms are of vital importance in a prospective payment system. This paper employed the difference-in-differences method to estimate the impacts of a per diem system with inverted-U-shape rates on medical costs and the length of stay based on data from a health insurance institution. The supply side cost sharing mechanism worked so that the new payment system significantly reduced medical costs by 17.59 percent while the average length of stay varied little. After further analyzing the mechanism, we found that heterogeneous effects emerged mainly due to the special rates design. The reform decreased the cases that incurred relatively high medical costs and lengths of stay. However, cost shifting existed so that physicians could be motivated to provide unnecessary services to the patients who should have been discharged before the average length of stay. Therefore, payment rates in the per diem system require a sophisticated design to constrain its distortion to medical service provision even though medical expenditures were successfully contained.

Although there are many studies discussing the effect of Internet use on political participation, the literature has rarely focused on the relationship between the use of online-network groups and the political-participation intention in contemporary China. The discussion of this relationship is significant, as it offers a new perspective on reviewing the mobilization theory of media, especially in the context of online-network groups, and potentially provides a new channel for mobilizing a wider range of people for politics once the relationship is significant. This study aims to answer the following question: Can we predict the political-participation intention of Chinese citizens through the use of online-network groups? Based on the data of the China Social Survey 2019, this study uses the hierarchical logistic-regression method. The research finds that the specific online-network groups that can predict political-participation intention are mainly concentrated in the category of emotional relationships. Among them, although most of the online-network groups are positively correlated with political-participation intention, the possibility of generating political-participation intention of those who join the relative network group is significantly lower than for those who do not. The virtual connection built by online communication technology, the social relations, and the influence of social groups on individuals can help to explain the correlation between them.