Which part of community social capital is related to life satisfaction and self-rated health? A multilevel analysis based on a nationwide mail survey in Japan.

This paper aims to clarify the association between various social capital components at the municipal level (community social capital) and two quality-of-life factors at the individual level [individual self-rated life satisfaction and self-rated health (SRH)] based on data from a nationwide social capital survey that the authors carried out in 2013 in Japan (N = 3406 in 99 municipalities). The survey covers residents in Japan between the ages of 20 and 79 years. We focus on both contextual social capital and household income inequality in terms of the Gini coefficient at the municipality level since, to the best of our knowledge, no paper has explicitly dealt with municipalities in Japan as the units of contextual social capital and the Gini. Our analyses show that the subjective life satisfaction of individuals, after controlling for socioeconomic status and health at the individual level, is associate with both an income gap and social capital at the municipal level. Every component of community social capital in this study except for generalized reciprocity, both cognitive (generalized trust, particularized trust, and particularized reciprocity), and structural (three types of group participation and daily contacts with neighbors, friends/acquaintances, and colleagues), and the Gini coefficient on earned income were associated with self-rated life satisfaction at the individual level with statistical significance. However, SRH is associated only with cognitive social capital at the community level. SRH has no significant association with structural components of community social capital or with a community income gap in terms of the Gini coefficient on personal income. Judging from the results of estimates in the study, most of the components of community social capital at the municipal level seem to play an important role in enhancing self-rated life satisfaction. Life satisfaction may be associated with the broad atmosphere of the municipal level where one resides, while SRH is associated with cognitive social capital rather than structural social capital. However, the difference in the impact of contextual social capital between the two QOL indices may indicate the importance of considering a proper contextual level that is suitable for the outcome.