Payment expectations for research participation among subjects who tell the truth, subjects who conceal information, and subjects who fabricate information

Subjects expected $20 on average to complete the least risky and least burdensome procedure. Subjects' expectations for payment consistently increased with greater procedure risks. Subjects who denied using deception to enroll in studies refused more procedures than subjects who reported using deception. Among subjects who used deception, the rate of procedure refusal increased with procedure risks, suggesting that these subjects have some risk aversion and may act to protect themselves from undue inducement. Although subjects expect greater payments for more risky procedures, ethical considerations for limiting undue inducement may prevent researchers from meeting subjects' expectations. Subjects who use deceptive practices appear to be more risk-tolerant than subjects who deny using deception; nonetheless, these deceptive subjects also exercise some risk aversion when they refuse higher-risk procedures. These subjects may be able to protect themselves from undue inducement by refusing procedures that exceed their risk tolerance.