RT Journal Article SR Electronic T1 Why high-risk, non-expected-utility-maximising gambles can be rational and beneficial: the case of HIV cure studies JF Journal of Medical Ethics JO J Med Ethics FD BMJ Publishing Group Ltd and Institute of Medical Ethics SP 90 OP 95 DO 10.1136/medethics-2015-103118 VO 43 IS 2 A1 Lara Buchak YR 2017 UL http://jme.bmj.com/content/43/2/90.abstract AB Some early phase clinical studies of candidate HIV cure and remission interventions appear to have adverse medical risk–benefit ratios for participants. Why, then, do people participate? And is it ethically permissible to allow them to participate? Recent work in decision theory sheds light on both of these questions, by casting doubt on the idea that rational individuals prefer choices that maximise expected utility, and therefore by casting doubt on the idea that researchers have an ethical obligation not to enrol participants in studies with high risk–benefit ratios. This work supports the view that researchers should instead defer to the considered preferences of the participants themselves. This essay briefly explains this recent work, and then explores its application to these two questions in more detail.