While collecting high quality data from physicians is critical, response rates for physician surveys are frequently low. A proven method for increasing response in mail surveys is to provide a small, prepaid monetary incentive in the initial mailing.
More recently, UWSC researchers have begun experimenting with adding a second cash incentive in a follow-up contact in order to increase participation among more reluctant respondents. To assess the effects of sequential incentives on response rates, data quality, sample representativeness, and costs, physicians were randomly assigned to treatments that crossed the amount of a first ($5 or $10) and second ($0, $5, or $10) incentive. Overall, second incentives were associated with higher response rates and lower costs, and while they had no effect on item nonresponse, they increased sample representativeness.
Bottom line: To maximize response rates, decrease costs, and potentially lower nonresponse bias, if you have $10 to spend on incentives, distribute the amounts in $5 increments; if you have $15 to spend, sequence the amounts in $5 and $10 increments.
View the publication
Dykema, Jennifer, John Stevenson, Nadia Assad, Chad Kniss, and Catherine A. Taylor. 2020. “Effects of Sequential Prepaid Incentives on Response Rates, Data Quality, Sample Representativeness, and Costs in a Mail Survey of Physicians.” Evaluation & the Health Professions. https://doi.org/10.1177%2F0163278720958186