CHARITIES, NO - LOTTERIES, NO - CASH YES - MAIN EFFECTS AND INTERACTIONS IN A CANADIAN INCENTIVES EXPERIMENT

The effects on response rates to mail surveys of prepayment cash incen tives, charitable donations, and the chance to win a lottery prize are examined in a true experimental design. A survey on environmental iss ues was conducted during the fall of 1994 among 3,088 households drawn from the Grand River watershed region of southwestern Ontario, Canada . The 20-cell incentives experiment crossed three levels of prepaid mo netary cash incentive ($2, $5, and $10) with a control group (no cash incentive), plus the offer to make a charitable donation ranging from $2 to $10 on behalf of the respondent, or participation in a lottery f or prizes of $200. The overall response rate to the survey, with three follow-ups, was 70.7 percent with the effects of the prepaid cash rew ards demonstrated,but not those for the lottery or charitable donation s. Logistic regression analysis of response rate supports a main effec ts model for cash incentives but does not support either of two altern ative models for main effects of the lottery and charitable donations or interactions. Further analysis demonstrates a pattern of earlier re sponse as a result of prepaid incentives. The findings are discussed i n terms of their cost-benefit implications and with respect to concept ualizations of respondents' motives for completing mail questionnaires .