This study explores the relationship between volunteers' psychological capital and their commitment to volunteering. We tested whether volunteers' psychological capital had a positive predictive effect on volunteering and whether this effect was mediated by organizational commitment, role identification, or perceived social support. A sample of 1165 volunteers who were registered in the national volunteer service information system of China were recruited in the study. The results showed a significant and positive relationship between volunteers' psychological capital, volunteering, role identification, perceived social support, and organizational commitment. Volunteers' psychological capital not only had a direct effect on volunteering but also affected volunteering through the mediating role of organizational commitment. Additionally, the influence of the volunteers' psychological capital on organizational commitment was affected by the joint moderated effect of role identification and perceived social support. Volunteers with low role identification and low perceived social support, high role identification and low perceived social support, and low role identification and high perceived social support committed to their volunteer organization faster when they had a high level of psychological capital; whereas, volunteers with high role identification and high perceived social support committed to their volunteer organization faster when they had a low level of psychological capital.

This study explored the role of perceived social support and voluntary motivation in the effect of psychological capital of volunteers on volunteering behavior. A sample of 1,165 volunteers who were registered in the China Voluntary Service Information System was investigated using a self-reported questionnaire, showing that the psychological capital, perceived social support, voluntary motivation, and volunteering behavior of the volunteers were significantly and positively related to each other. The psychological capital of the volunteers affected volunteering behavior not only directly, but also indirectly through the mediating role of voluntary motivation. Moreover, perceived social support and voluntary motivation also played a chain role in the relationship between the psychological capital and volunteering behavior of the volunteers. Therefore, increasing the psychological capital of the volunteers should promote their perceived social support and inspire voluntary motivation, in turn affecting their volunteering behavior.