Charities, No; Lotteries, No; Cash, Yes: Main Effects and Interactions in a Canadian Incentives Experiment

TLDR

The study examines cost‑benefit implications and respondents’ motives for completing mail questionnaires. The effects of prepaid cash incentives, charitable donations, and lottery participation on mail‑survey response rates were examined in a true experimental design. A 20‑cell experiment with 3,088 households in southwestern Ontario crossed prepaid cash incentives ($2, $5, $10, none), charitable donations ($2–$10), and a $200 lottery to test their effects on response rates. Cash incentives increased response rates (overall 70.7%) and prompted earlier replies, whereas lottery and charitable donation offers had no significant effect, as confirmed by logistic regression.

Abstract

The effects on response rates to mail surveys of prepayment cash incentives, charitable donations, and the chance to win a lottery prize are examined in a true experimental design. A survey on environmental issues 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 monetary 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 for 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 rewards demonstrated, but not those for the lottery or charitable donations. Logistic regression analysis of response rate supports a main effects model for cash incentives but does not support either of two alternative models for main effects of the lottery and charitable donations or interactions. Further analysis demonstrates a pattern of earlier response as a result of prepaid incentives. The findings are discussed in terms of their cost-benefit implications and with respect to conceptualizations of respondents' motives for completing mail questionnaires.