[The ethics of health nudges: a discussion about their acceptability in public health.]

In behavioral science, the term nudge refers to any aspect of decision architecture that predictably alters people's behavior to improve the chooser's own welfare without forbidding or significantly restricting their choices. Its promoters invoke libertarian paternalism, which means, on the one hand, that the behavior of the individual is guided without counting on his autonomy, but, on the other hand, that this form of influence does not reach the point of restricting freedom of choice when it is manifest. This paper analyzes the role of nudges in the field of health policies. A cognitive analysis of these nudges is carried out and are distinguished the clinical nudges (those that take place within the healthcare professional and patient relationship) from the public health nudges (specific to public health policies). The ethical aspects of both categories of nudge will be analyzed to point out some of their virtues and the ethical challenges they face. This study focuses in particular on public health nudges, to consider whether it is reasonable, and with what limits, their implementation in health crises (for example, pandemics). Analyzing that public policies face the dilemma between preserving freedom at the expense of health or, on the contrary, prioritize health to the point of limiting freedom. It is raised whether in this context greater restrictions on individual freedoms should be allowed (for example, through mandatory lockdowns and quarantines, imposed vaccinations, forced tests) or whether to use nudges as an intermediate solution and less harmful to individual rights to promote health measures.