Low response rates and thus a certain level of nonignorable unit nonresponse in household surveys cause growing uncertainty about the reliability and validity of the results. Within the scope of “Mobility in Cities – SrV 2013”, 4.802 persons who had not participated in the main study were successfully encouraged to fill in an abbreviated questionnaire. Hence, it was possible to collect important information concerning the nonrespondent's person and daily mobility. The analysis methodology used is based on multivariate analysis tools. It allows for explanations of failure mechanisms, effectiveness of weighting procedures as well as their consequences regarding potential bias of estimators.