Treatment of non-response in longitudinal network studies

The collection of longitudinal data on complete social networks often faces the problem of actor nonresponse. The resulting incomplete data pose a challenge to statistical analysis, as there typically is no natural way to treat the missing cases. This paper examines the problems caused by actors missing as nominators, but still occurring as nominees, in complete, directed networksmeasured in a panel design. In the framework of stochastic actor-drivenmodels for network change (“SIENAmodels”), differentmethods to cope with such incomplete data are investigated. Data on a friendship network among female high school students are used to illustrate the procedures. Missing data problems related to early panel exit