The ethics of risk displacement in research and public policy.

We identify three distinct ethical problems that can arise with risk displacement. Risk displacement is the shifting of extant risk from one or more individuals to other individual(s) such that the reduction of risk to the first group is causally implicated in increasing risk to the second group. These problems are: concentration of risk in inequitable ways; transfer of risk to already vulnerable or disadvantaged populations; and exercise of undue influence over potential research participants. The first two arise in both public policy and research initiatives, whereas the third is a special concern that only applies to research initiatives. We argue that when one or more of these is of high magnitude, then the study or policy intervention may be ethically wrong. Finally, we conclude that although some risk displacement is ethically permissible, researchers and policymakers still have ethical reasons to reduce the magnitude of these problems.