THE INTERACTIVE EFFECTS OF MONETARY INCENTIVE JUSTIFICATION AND QUESTIONNAIRE LENGTH ON MAIL SURVEY RESPONSE RATES

An experiment was conducted in which a survey questionnaire and a $1.00 incentive were sent to 200 randomly selected residents of a midwestern city. For half of the respondents, the enclosed monetary incentive was justified in a cover letter as an attempt to induce feelings of obligation to return the questionnaire (equity-salient condition), whereas for the other half of the respondents, the incentive was justified as an appreciative gesture (standard condition). Furthermore, some subjects received a short questionnaire, whereas the rest received a long questionnaire. Response rates were assessed by condition. As predicted, the equity-salient appeal produced a significantly higher response rate than the standard appeal, but only for subjects who received the short questionnaire. Results are discussed in terms of personal equity theory. (C) 1994 John Wiley & Sons, Inc.