Age differences in social network participation.

Differences in participation in social networks were analyzed as a function of age, drawing on a theoretical model of substitution processes. Using an empirical approach from the study of participation in voluntary organizations, I separated the direct effects of age from indirect effects via age-based declines in resources. The results show that a substantial proportion of the age-based decrease in level of activity in social networks was due to declines in resources, but similar analyses for the sources of participation in networks showed effects of age that persisted after controlling for resources. These results point to some important distinctions among measures of social networks.