DOI: 10.1177/0163278720958186 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, 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 (N = 1,500) were randomly assigned to treatments that crossed the amount of a first ($5 or $10) and second ($0, $5, or $10) incentive to form the following groups: Group $5/$5; Group $5/$10; Group $10/$0; Group $10/$5; and Group $10/$10. Overall, second incentives were associated with higher response rates and lower costs per completed survey, and while they had no effect on item nonresponse, they increased sample representativeness.
Dykema, J., J. Stevenson, N. Assad, C. Kniss, and C. A. Taylor. Effects of Sequential Prepaid Incentives on Response Rates, Data Quality, Sample Representativeness, and Costs in a Mail Survey of Physicians. Vol. 44, no. 3, Evaluation & the Health Professions, 2021.