The promotion mechanism of physical and mental health of the elderly in China: the impact of the digital divide and social capital.

With the deep integration of population aging and digital transformation, the society has benefit from digital dividend, while also giving rise to the issue of the aging population's digital divide.This study is based on the three-level digital divide theory analysis framework, concentrating on the impact of the digital divide on elderly people's health during the Covid-19 pandemic in China, conducts multiple regression analysis, and uses the instrumental variable method and PSM propensity matching for robustness testing. Constructs a multiple mediation model of digital skill-social capital-elderly health, and applies Bootstrap-based structural equation model(SEM) to analyze and examine the influencing mechanism and pathway of digital skill on elderly people's physical and mental health. The research results indicate that: (1) From self-rated health, physical health, and mental health three aspects, digital skill significantly promotes elderly people's health, moreover, the elderly health is negatively impacted by the digital divide. (2) Among the elderly, their physical and psychological health are linked by a "cyclic cumulative causal effect". (3) The effect of digital skill on elderly people's health exists urban-rural difference. (4) A mediating effect of social capital in the connection between digital skill and elderly people's health. Digital skill enhances the state of elderly people's health by enriching relational and structural social capital, and aged adults' health is negatively impacted by a reduction in cognitive social capital. Therefore, in the future, it is necessary to fully leverage the health promotion function of digital skill, broaden senior citizens' social network, promote their social participation, bridge the senior citizens' digital divide, so then realize healthy aging and sustainable development.