Paying Research Participants: Regulatory Uncertainty, Conceptual Confusion, and a Path Forward.

The practice of offering payment to individuals in exchange for their participation in clinical research is widespread and longstanding. Nevertheless, such payment remains the source of substantial debate, in particular about whether or the extent to which offers of payment coerce and/or unduly induce individuals to participate. Yet, the various laws, regulations, and ethical guidelines that govern the conduct of human subjects research offer relatively little in the way of specific guidance regarding what makes a payment offer ethically acceptable-or not. Moreover, there is a lack of definitional agreement regarding what the terms coercion and undue inducement mean in the human subjects research context. It is, therefore, unsurprising that investigators and Institutional Review Boards (IRBs) experience confusion about how to evaluate offers of payment, and lean toward conservative approaches. These trends are exemplified by our pilot data regarding the ways in which some IRB members and investigators (mis)understand the concepts of coercion and undue inducement, as well as the ways in which certain research institutions oversee offers of payment at a local level. This article systematically examines the legal and ethical dimensions of offering payment to research participants. It argues that many concerns about offers of payment to research participants can be attributed to the misguided view that such offers ought to be treated differently than offers of payment in other contexts, a form of "research exceptionalism." We show that rejection of research exceptionalism with respect to payment helps settle open debates about both how best to define coercion and undue influence, and how to understand the relation between these concepts and offers of payment. We argue for adoption of our preferred definitions, ideally by regulatory authorities, and against the conventional conservatism toward payment of research participants. Instead, we draw attention to the rarely asked, even radical, question: are research participants paid enough? We conclude by arguing that we ought to change the default to favor, rather than encourage suspicion of, offers of payment to research participants.