Social participation and life satisfaction among middle-aged and elderly people in China: the mediating role of depression and the moderating role of relative income

The primary objective of this study is to explore the mediating role of depression in the relationship between social participation and life satisfaction among middle-aged and elderly individuals, as well as the moderating role of relative income. To this end, we used the China Health and Retirement Longitudinal Study (CHARLS) for regression analysis to investigate whether social participation affects life satisfaction. The CHARLS data cover 150 county-level units, 450 village-level units, and 17,000 people in about 10,000 households. The "Life_satis = alpha + beta*Soc_parti + gamma*X + epsilon" model was used to evaluate the effect of social participation on life satisfaction. The BK method was used to test whether depression mediates between social participation and life satisfaction.Nowell et al.'s (2016) three-step test was used to determine whether relative income moderates the influence path. Our results show that social participation significantly promotes life satisfaction, but the impact of social participation on rural residents was stronger than on urban residents. Depression mediated the positive impact of social participation on the life satisfaction of middle-aged and elderly people. Relative income negatively moderated the positive impact of social participation on depression. Relative income negatively moderated the positive impact of depression on residents' life satisfaction. We suggest that promoting social participation, managing and alleviating symptoms of depression, and increasing levels of relative income are key factors in positive aging.