In June, The Improve Group described our experiences using incentives to encourage people to participate in surveys and other evaluation activities. We highlighted the benefits of knowing your audience and attracting their attention.
This month, we share major findings from research on incentives conducted by our New Sector Alliance Fellow, P.J. Murphy. Several researchers have used large-scale surveys to test different incentive approaches, including:
- Value, ranging from nominal to over $10
- Distributing small amounts to everyone vs. offering a larger, lottery-style incentive
- Timing, from initial request (prepaid) to following survey submission (promised)
Here are some of the major findings from the research:
- Instant Gratification! Prepaid incentives are more effective than promised incentives—sometimes. Have you ever received an invitation or an actual survey that had cash attached to it? If so, the researchers are following the 1993 meta-analysis of Allan Church, which has since been confirmed by several researchers. But times have changed a bit. Recent analysis of different modes shows that there is no difference between prepaid and promised incentives for online surveys, like there is for mailed surveys. This may be because respondents thought it was difficult to gather their cash online. And if your respondents already know you, as in a longitudinal study, they are just as likely to respond to a prepaid incentive as they are to a promised incentive.
- How much is enough? The relationship between response rate and incentive size is positive. But the increase in response rate per increase in incentive amount becomes less powerful the larger the incentive amount. Researchers have tested different amounts and found that while each dollar added to an incentive increases response rates, the increase tapers off after $4 or $5.
- Cash is King! Cash incentives are often more preferable than lottery, charity, or other incentives; in fact, some researchers have found that non-cash incentives have no effect on response rates. However, there are several contexts where other incentives do work as well as cash. For example, when you know your audience well and the incentive is closely matched to their interests, or when you are offering web respondents a chance to participate in a lottery.
- Know your audience! Know your target population and determine what factors motivate them to participate. Respondents will be motivated by several factors when participating in your evaluation: their relationship with your organization; the burden of participating; and their perceptions of how valuable their responses are. As we have found in our research and practice, not all populations respond equally well to incentives. For example, one researcher found that a higher incentive had an inverse effect on survey participation among women enrolled in college. When your population has a negative reaction to incentives, there is a risk of increasing response bias in your results.
Based on our study of this issue and our practice in the field, we recommend following a few steps when selecting incentives:
- Develop an overall budget for incentives that is rational and appropriate for the organization
- Learn about your population, including their preferences and motivations
- Engage a sample of potential respondents to brainstorm or help refine your incentive plan
- Clearly articulate to respondents the reasons for the evaluation, why their response is needed, and why you chose to use an incentive
To view past articles on incentives visit: Participant Incentives can Save Time and Money