The Cost-Effectiveness of Alternative Advance Mailings in a Telephone Survey

Advance letters are being used increasingly to combat the decline in response rates, but their effectiveness depends partly on their being read. In the face of the post-9/11 anthrax mailing scare, the Office for Survey Research (OSR) converted to using advance postcards rather than advance letters. Subsequently, the OSR conducted an experiment to test the effectiveness of sending letters, postcards, or nothing to directory-listed numbers selected in a large random digit dial (RDD) telephone survey. In terms of response rates, the results clearly indicate that sending advance letters is more effective than sending postcards, which, in turn, is more effective than sending nothing. A detailed cost-effectiveness evaluation indicates that sending letters actually saves money, despite the increased costs associated with the mailings, compared to sending postcards; sending postcards is also more cost-effective than not sending anything.