Before revision: Our study seeks to identify the social contagion of in-group gifts: if gifts trigger their recipients to send more gifts subsequently, the actual impact of a gift on group dynamics would be greatly amplified. Causal identification of contagion is always challenging in observational data; To identify gift contagion , we leverage a natural experiment using a large sample of 36 million online red packets sent within 174,131 chat groups on WeChat, one of the largest social network services worldwide .
After revision: Gifts are important instruments for forming bonds in interpersonal relationships. Our study analyzes the phenomenon of gift contagion in online groups. Gift contagion encourages social bonds of prompting further gifts; it may also promote group interaction and solidarity. Using data on 36 million online red packets sent within 174,131 chat groups on WeChat, one of the largest social network services worldwide .