The Heterogeneous Impact of Internet Use on Older People's Mental Health: An Instrumental Variable Quantile Regression Analysis.

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. Data come from the 2018 China Health Retirement Longitudinal Study ( = 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). 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. 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.