Cost effectiveness of pre- and post-paid incentives for mail survey response

Abstract

While incentives improve survey response rates, they entail significant costs for the researcher. A mail survey study randomized across three incentive conditions ($2 pre-paid, $10 post-paid, and $20 post-paid), found that households in the $2 pre-paid condition were more likely to respond than the $10 post-paid condition (48.5% vs. 33.5%, β = -0.536, SE = 0.154, p < .001) and the $20 post-paid condition (48.5% vs. 42.4%, β = -0.305, SE = 0.10, p = 0.11). The $2 pre-paid condition was also more cost-effective than the $10 and $20 post-paid conditions (cost-per-complete of $15.35 vs. $26.67 and $34.40, respectively). The results of this study show that a small pre-paid incentive is generally most effective for maximizing both response rates and costs. The data from the study is also used to construct a model to forecast cost-efficiency for variable eligibility conditions, through a factor-adjusted response rate.