Abstract
Objectives: Whether Internet use improves older people's health is an open question. This study empirically investigated the impact of Internet use on older people's mental health with a focus on the heterogeneity among subgroups. Method: Data come from the 2018 China Health Retirement Longitudinal Study (n = 8,505). An instrumental variable quantile regression method (IVQR) combines the instrumental variable and quantile regression to resolve the endogeneity and heterogeneity generally challenged in ordinary least squares (OLS). Results: Although Internet use generally improves older people's mental health, there is enormous heterogeneity in the effects on older adults with different mental health conditions. Specifically, Internet use only has a mitigating impact on older adults with poor mental health. Those heterogeneities are also found between rural and urban residents but not between genders. Conclusion: Our findings shed light on active and healthy aging strategies. Two policy priorities include, on the one hand, the Internet user environment should be improved in parallel with Internet technology; on the other hand, multiple measurements are urgent to be developed to deal with the heterogeneity and unevenness of the impact of Internet technology on older people.