Vulnerable Populations

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Below are some general guidelines for and examples of compensation considerations for certain vulnerable populations, as well as examples of forms or methods of compensation that should be avoided.


In the U.S. “minor” typically refers to youth under the age of 18, but the age at which youth can legally provide consent does vary across jurisdictions. It is generally acceptable to compensate youth (and/or their parents) for their participation in research. When conducting research with minors, researchers should consider the following:

  • Because parents have the authority to grant permission for their children to participate in research, compensation may entice a parent to allow their child to participate against the parent’s better judgment, and/or pressure their child to participate in the research. Often, researchers can avoid undue influence of and by the parents by reimbursing them for expenses associated with their child’s research (e.g. transportation to the lab), and offering the child a token of appreciation at the end of the study.
  • Compensation must be appropriate for the age and/or developmental stage, and context of the study. For example, a small toy may be appropriate for a young child, while a gift card may be more appropriate for a teenager. Offering cash to youth should be approached with sensitivity to matters such as how the child might view the value of the cash, and whether or not the child’s possession of the cash could put them at risk of harm.
  • Consideration of allergies, health hazards, and food handling requirements must be made when offering candy or other forms of food.
  • Youth are particularly susceptible to peer pressure. Researchers should design their study and the offer of compensation so that peer pressure to participate or “get what others are getting” is minimized.


The terms of any individuals' incarceration and/or the site of their incarceration may restrict the amount, form, and method of compensation that is permissible. Researchers must check with the relevant penal institution/authorities about restrictions on compensation prior to developing their protocol and plan for compensation. Additionally, federal regulations recognize that prisoners experience constraints that may affect their ability to make a truly voluntary decision about participation in research and implore IRBs to ensure proposed research is not coercive. The following must be taken into account when proposing compensation for prisoners:

  • The amount and method of compensation for participation must be made with consideration of the payment structure within the facility.
  • When possible, the offer of compensation should be conveyed privately to individuals to help promote the safety of participants.
  • Participation in research cannot be induced with promises of additional institutional privileges.

Low income and other socially/materially vulnerable populations

Creating opportunities for all members of society to participate in research is a matter of justice. As already discussed, however, compensation should not be so great that it obfuscates the true risks, costs and benefits of participation, or entices participants to engage in activities to which they would be averse or would otherwise find objectionable. Compensation should be tailored to the resources and vulnerabilities of the population. The following considerations must be made:

  • The method of compensation must be appropriate for the participants’ circumstances, which could include no or limited access to email, bank accounts, particular retailers, etc. For example, a gift card to a grocery store serving the neighborhood where participants reside may be more appropriate than an Amazon gift card.
  • When low income status intersects with other material or social vulnerabilities, such as homelessness, chronic illness, or minority social status, special care must be given to simultaneously avoid either exploiting potential participants by virtue of under payment, or unduly influencing them by offering excessive compensation. Individuals or organizations who work with those populations may be able to provide guidance on what amount, form and method of compensation is appropriate.

Undocumented populations

Researchers who include individuals who lack legal status must be aware that the gathering of individually identifiable information and tracking the compensation may put these individuals at greater risk. These risks must be mitigated to the greatest extent possible, which may necessitate offering something other than monetary remuneration.