Recruiting people to participate in a survey is like hitting a baseball. Your goal is to connect, and execution is difficult. Just as batters face new challenges—harder-throwing pitchers and pitcher specialization—researchers face declining survey response rates, increasing costs, and competition for distracted subjects’ attention.

For respondents, participating in surveys requires time and effort. Long surveys and those covering sensitive topics present greater burden. Prepaid incentives are one of the most reliable tools researchers can use to increase survey participation. We sought to determine the optimal incentive amount and whether splitting incentives across multiple mailings improves engagement or just adds cost without benefit.

NORC partnered with the Board of Governors of the Federal Reserve System to conduct a rigorous experiment of optimal cash incentive strategies. We embedded a large-scale, pre-registered field experiment into the 2022 Survey of Consumer Finances (SCF) to answer these questions. The results provide the most rigorous evidence to date regarding the optimal structure and value of pre-incentives for boosting early survey response. We find support for two principles with clear implications for future surveys:

1. Increased incentive amounts spur early response without harming data quality.
2. Straightforward designs reduce interviewer burden and accelerate survey participation.

The SCF offers a unique opportunity to evaluate recruitment behavior for higher-burden surveys. The survey asks respondents for intricate data on wealth, liabilities, retirement, education loans, and other financial topics affecting U.S. households. The main questionnaire generates roughly 20,000 variables.

Collecting this complex information relies on fastidious interviewers who carefully guide respondents through a lengthy questionnaire. This level of burden provides justification for larger monetary incentives and experimentation involving different treatment structures, features that are not well understood from past studies.

We randomly assigned over 8,600 U.S. households, stratified by geography via national frame, to one of six groups. For each group, we tested a different incentive approach combining variations of these three dimensions:

• Value: 5 dollars, 10 dollars, or 15 dollars in a single payment
• Sequence: One 10-dollar payment vs. two 5-dollar payments
• Change: 5 dollars then 10 dollars, or 10 dollars then 5 dollars 

The most straightforward test examined whether a single 10-dollar or 15-dollar payment impacted outcomes differently than a single 5-dollar payment. Second, we tested for differences in impact when varying the timing of delivery (one 10-dollar payment versus two 5-dollar payments). Finally, we tested whether increasing or decreasing the value of the second payment relative to the first matters). Our experiment’s large total sample allowed robust sample sizes of at least 1,200 households per group, an important attribute for statistical power.

All households received two mailings over two weeks. Each envelope had a clear window on the back showing the cash incentive inside—so recipients could see the money and its value immediately. We sent the second mailing, including incentives for most of the experiment groups, two weeks after the first, regardless of whether they had already responded.

All households were also eligible for a 10-dollar conditional incentive for providing contact info and a 75-dollar post-paid incentive for completing the interview (identical across groups). We measured results eight weeks after the first mailing. This early timeframe let us see the incentive effect clearly, before differences in interviewer follow-up and other factors complicated the picture. The full SCF field period typically lasts at least eight months.

• Higher prepaid incentives increased response rates. Raising the prepaid incentive from 5 dollars to 15 dollars increased response rates by approximately 2 to 3 percentage points—about one-third of the baseline rate—without measurable effects on data quality or interviewer burden.
• Higher incentives did not compromise data quality. Item response rates and financial reporting quality were consistent across all groups.
• Splitting incentives did not improve outcomes. Two 5-dollar payments did not increase survey response relative to a single 10-dollar payment and increased field time and interviewer workload. A single, upfront incentive led to faster responses and a higher response rate.

Our findings can help researchers and others who use surveys to inform decision-making. Our results support two general principles:

1. Increased incentive amounts provide measurable gains in early response with no adverse data quality effects.
2. Simple, upfront designs reduce interviewer burden and accelerate survey response. Splitting incentives adds operational complexity and increases field time without boosting early participation.

Survey recruitment remains challenging, but our SCF experiment offers evidence-based strategies to improve the odds of connecting with participants.