Revisiting the Effect of Conditional and Unconditional Incentives on Mail Survey Response Rates

A randomized experiment (N = 3,037) examines the impact of conditional and unconditional monetary incentives on response rates to a mail survey in a contemporary context. This is the first large sample study in 10 years to examine the effect of monetary incentives on survey response. Providing monetary incentives of any kind significantly increases response rates by 5pp to 18pp compared to a no-incentive control group. Unlike in past research, when payment amounts are equivalent, unconditional and conditional incentives yield similar response rates, suggesting that conditional incentives may be substantially more cost effective than unconditional incentives. We also find that greater payment amounts may elicit higher response rates, even when the incentive is conditional upon survey response.