A comparison of email networks and off-line social networks: A study of a medium-sized bank

Rebeka Lex, University of Lugano
Balazs Kovacs, University of Lugano
Andras Vicsek, Maven7


Recently there has been a surge in the availability of online data concerning the connections among people, and these online data are now widely used to map the social structure of communities. There has been less research, however, on how these new types of relational data correspond to classical measures of social networks. To fill this gap, we aim to contrast the structure of an email network with the underlying friendship, communication, and advice seeking networks. Our dataset contains email communications among employees of a medium-sized bank, and of a survey of the ego networks of the employees. Through calculating correlations with QAP standard errors and estimating exponential random graph (ERG) models, we find that although the email network is related to the survey-based social networks, emails are not perfect proxies for survey data: while off-line social networks are strongly shaped by gender, tenure, and hierarchical boundaries, the role of these boundaries are much weaker in the email network.