This paper investigates what kinds of social networks nudge volunteering by applying social network analysis. Unique Japanese data with various social network variables are used to explore the association between formal and informal social networks and volunteering. The results show that “attending meetings of neighborhood associations” and “enrollment in a membership association,” which involve forms of formal social networks, are positively correlated with the probability of both “any volunteering” and five kinds of volunteering. “Frequency of meals with friends,” an indicator of informal social networks, has statistical significance for volunteering. Notably, friendships, even if meals are infrequent, are enough to lead to volunteering opportunities. The author thus concludes that greater social participation can be fostered by promoting not only organizational assistance but also friendships.

本文通过应用社交网络分析来研究哪些类型的社交网络可以推动志愿服务。使用具有各种社交网络变量的独特日本数据来探索正式和非正式社交网络与志愿服务之间的关联。结果显示，“参加居委会会议”和“加入会员协会”等涉及正式社交网络的形式，与“任何志愿服务”和五种志愿服务的概率呈正相关。“与朋友一起吃饭的频率”是非正式社交网络的一个指标，对志愿服务具有统计意义。值得注意的是，即使很少吃饭，友谊也足以带来志愿服务的机会。因此，作者得出的结论是，不仅可以通过促进组织援助而且可以通过促进友谊来促进更大的社会参与。