Based on data from the 2023 China Longitudinal Aging Social Survey (CLASS), this study empirically examines the impact of the digital divide on older adults' consumption and its underlying mechanisms. The results show that a high-level digital divide significantly suppresses older adults' consumption. This negative effect is mediated by older adults' negative perceptions and attitudes toward aging. The moderating effects analysis suggests that social participation, family and peer support for older adults' Internet use can mitigate the suppressive effect of a high-level digital divide on older adults' consumption. The moderating effects vary depending on whether there are non-older adults in the household. The heterogeneity analysis shows that the suppressive effect of a high-level digital divide on consumption is more pronounced among the oldest-old, rural older adults, and those residing in economically underdeveloped regions. This study emphasizes the need to strengthen digital infrastructure, promote the age-friendly digital design, foster intergenerational digital literacy support within families, and strengthen social support and participation in community activities. Furthermore, a stratified and categorized digital inclusion support system should be established to meet the diverse consumption needs of different older adult populations.

The expanding population and the transformation of consumption structure are the key factors that affect the sustainable development of national economy and the sustainable use of re- sources in an all-round way．This paper measures the environmental efficiency by super-efficiency DEA method，and studies the impact of population size and consumption structure on environmental efficiency based on the STIRPAT model．The results show that from 2000 to 2013，the environmental efficiency of China's provinces demonstrated a declining trend of volatility with large regional differences．At this stage，the expansion of the population size has a negative impact on the environmental efficiency in China．Meanwhile，consumption structure，as an important intermediate variable linking population and environment，shows different relationship patterns with environmental efficiency according to different types of consumption structure．Specifically，the relationship between subsistence and enjoyment consumption with the environmental efficiency has a u-shape，the inflection points of which are 60． 18% and 29. 20% ， while the relationship between development consumption and the environmental efficiency shows a line- ar positive correlation．With the upgrade of consumption structure，the negative impact of population size on environmental efficiency will be altered．