A sample of 301 single parents in Guangzhou, Chiia enabled a study of relationships between distress on one hand and social pressure and social support on the other. Confirmatory factor analysis showed that social pressure and social support, including emotional support and instrumental support, were only weakly correlated. They were shown to have equal conhibution to distress, which included depression and anxiety. Distress was positively related to social pressure and negatively related to social support. No sex differential was detected for these relationships. Results indicate the importance of the so-

Purpose Encouraging college students to volunteer is a supposed but uncharted way to contribute to their career commitment. Clarifying the ways of the contribution is therefore necessary. From the social capital perspective, volunteering and network density among friends represent social capital to reinforce each other. Thus, the purpose of this paper is to study the enhancement of the contribution by the density. Design/methodology/approach The examination employs a two-wave panel survey of 410 university students to estimate the effects of volunteering and friend network density at Wave 1 on career commitment at Wave 2. Essentially, the examination adjusted for biases due to sample attrition and self-selection into volunteering. Findings Volunteering at Wave 1 showed a significant contribution to career commitment at Wave 2. Moreover, the contribution significantly increased with friend network density at Wave 1. Research limitations/implications Findings from this panel survey of university students in Hong Kong require future research for substantiation. For instance, such research can apply an experimental design to volunteering to guarantee the internal validity of the contribution of volunteering. Practical implications Social capital theory is applicable to the promotion of career commitment. Specifically, optimizing the strength of social capital through the combination of volunteering and friendship is promising. Originality/value Empirical support for the application of social capital theory to career development is evident. Particularly, the joint contribution of volunteering and friendship is demonstrable.