The Impact of Digital Infrastructure on Mental Health and Inequality Among Older Adults: Evidence from Longitudinal Panel Data in China

Rapid population aging and uneven digital development pose new challenges to social sustainability and health equity. This study investigates the impact of digital infrastructure on mental health and health inequality among older adults in China. Using panel data from 279 prefecture-level cities between 2013 and 2020, we apply fixed-effects and instrumental variable (IV) models to identify the causal effects of digital infrastructure development. The results indicate that improved digital infrastructure significantly reduces depressive symptoms (β = −9.31, p < 0.01) and decreases mental health inequality (β = −0.187, p < 0.01) among older adults. Mediation analyses reveal that bridging the digital divide, enhancing social participation, and improving self-rated health partially explain these effects. The impact is more pronounced among women, younger older adults, and rural populations. These findings highlight the importance of promoting equitable access to digital infrastructure as part of public health and sustainable development strategies to address structural determinants of health inequality in aging societies..