17.    Can participants be paid? Researchers may pay research participants for their participation, but payment arrangements must be disclosed to the IRB and are subject to a stringent review. Payment arrangements affect the fairness of recruitment plans, the balance of risks and benefits, and the adequacy of informed consent. Although there are no fixed formulas for determining whether payment plans are acceptable, the IRB prohibits payment arrangements that appear to be coercive. Payment should not encourage participants to participate or continue to participate against their better judgment.

The amount paid to participants must correspond to the burdens of participation. For example, payment might defray parking charges or transportation costs. Payments may also be scaled to the time that participants spend in a study or to the biological materials they donate. The minimum wage provides a ready baseline for hourly rates for participation, and the Blood Bank's payment scale for plasma and other blood products offers a guideline for compensating participants for biological materials.

Researchers who are reluctant to pay cash may offer gift certificates or grocery vouchers. When children and adolescents are the participants, researchers sometimes reimburse parents for parking or transportation and give a token payment or gift certificate to the participant. Drawings and raffles are subject to the laws and regulations governing games of chance and are generally discouraged.

Participants should receive at least partial payment if they withdraw from a study. Withholding all payment until participation is complete is coercive. A modest lump sum can be paid after the participant's participation is complete if the arrangement is thoroughly documented in the consent form.