Recent Evidence On the Relationship Between Anonymity and Response Variables for Mail Surveys

Although most marketing researchers and texts recom mend guaranteeing respondents anonymity in mail surveys, empirical evidence on this issue is dated, and often is based on results from student or occupational samples. The present study examines the impact of anonymity on item omission, response bias, and response quality. Based on a represent ative sample of respondents from a Southern SMSA, it was found that lack of anonymity had minor effects on response variables. Anonymous respondents provided slightly less in formation to complex questions, and lower-income respond ents, nonwhites, and homeowners were more likely to identify themselves on the return envelope. Yet, the responses of these groups did not differ substantively from answers of other respondents on the range of questionnaire items examined.