Upfront Unconditional Monetary Incentives in Survey Nonresponse Reduction

In Simple Words

Enclosing a physical cash bill inside an initial survey envelope establishes an immediate psychological gesture of trust and reciprocity. This upfront gift motivates individuals to complete and return the survey far more effectively than offering a larger financial reward that is paid only after the completed survey is mailed back.

Research question

High nonresponse rates threaten the internal validity of empirical field studies by introducing nonresponse bias, particularly among wealthy individuals for whom standard post-completion survey monetary rewards offer minimal relative motivation.

Participants

Subsample of N = 594 initial nonresponding Massachusetts lottery players (297 winners, 297 nonwinners) re-contacted via Federal Express.

Study Design

Randomized field trial comparing an unconditional upfront $10 cash enclosure combined with a $40 conditional post-completion check versus a single $50 conditional post-completion check.

Results

The upfront $10 cash incentive produced a 23% response rate compared to 16% for the conditional $50 check alone (t-statistic = 1.81, p-value = 0.08), helping raise the study's overall response rate to 46% across mailings.

Takeaway

1. Include small unconditional upfront cash payments in survey mailings rather than relying solely on larger conditional post-completion financial promises when sampling hard-to-reach populations.

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