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

Multiple models guide researchers' payment practices but few studies have assessed subjects' expectations for payment. Payments in excess of subjects' expectations may result in undue inducement, while payments below these expectations may be associated with exploitation. Data on subjects' payment expectations will help inform practices to avoid undue inducement and exploitation. This study examined subjects' expectations for payment for common research procedures and explored the relationship between subjects' honesty and payment expectations. One-hundred subjects who participated in two or more studies in the last year reported the minimum payment they expect for completing study procedures. They were also asked about their use of deception while screening for studies. 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.