Which principle of the Belmont Report expresses the moral requirement for fair outcomes in the selection of research subjects?

The principle that expresses the moral requirement for fair outcomes in the selection of research subjects is Justice. This principle emphasizes the need for equitable distribution of both the benefits and burdens of research. The focus on Justice ensures that no particular group bears an undue share of the risks associated with research while others benefit disproportionately.

Justice is integral to the ethical conduct of research, particularly when vulnerable or marginalized populations are included. It drives researchers to consider how subjects are selected and to strive for inclusivity, ensuring that all groups have access to the benefits of research and that the risks involved are not unfairly allocated to disadvantaged populations.

In contrast, the other principles — Respect and Beneficence — while equally important, focus on different facets of ethical research conduct. Respect relates to the autonomy and dignity of individuals involved in research, while Beneficence is concerned with maximizing benefits and minimizing potential harm to participants. Accountability, while notable in research contexts, is not a principle outlined in the Belmont Report in the same way as the first three, which are foundational to ethical research practices.