Effects of Benefits Appeals, Mandatory Appeals, and Variations in Statements of Confidentiality on Completion Rates for Census Questionnaires

This study examines the effects of two different prominently displayed appeals in combination with two different prominently displayed confidentiality assurances on mail-back completion rates for census questionnaires. The experiment was carried out on a national probability sample of 30,000 household units, using occupant-addressed questionnaires that contained the content of the 1990 decennial census short form. Neither the benefits appeal nor the variation between two confidentiality assurances had a significant effect on completion rates. The mandatory appeal, however, significantly improved completion rates, even when it appeared on the envelope only.