Economic analysis of prevention behaviors in the face of health risks.

Summary Many people consider that since the development of curative medicine, prevention has occupied a secondary place in the French health system. Until then, the main concern was to ensure access to care rather than to promote a culture of prevention. In recent years, various health tragedies (blood transfusions, asbestos, heat waves, growth hormone, influenza epidemics, cancers, etc.) have raised public awareness of the concept of "health security" and have led to a new awareness of the problems of prevention. The use of prevention allows individuals and public authorities to exercise control over the health risks to which they are exposed and to carry out consequent actions with the aim of improving the state of health by avoiding the onset, development or aggravation of diseases or accidents, while encouraging individual and collective behaviors that can contribute to reducing health risks. One of the responses to health risks is to encourage individuals to be more preventive, because they are no longer just consumers of care but also producers of their own health. What is therefore the role of individuals and what is their share of responsibility in the prevention of health risks? Moreover, the prevention of health risks is part of an environment of ambiguity and uncertainty because the risks to which individuals are exposed are diverse and not always well known. It is therefore not easy to link a risk factor and a health effect with certainty in order to adopt appropriate preventive behaviour. In this context of uncertainty, many models of decision support, or representations of preferences have been proposed in recent years (Klibanoff et al.(2005), Bleichrodt and Eeckhoudt(2006) Machina(2009), Etner et al.(2011)). This thesis analyzes the prevention behaviors of individuals in the face of health risks while focusing on the proposed public prevention policies. It consists on the one hand of theoretical studies of prevention and health risk management behaviors using recent preference models. This work analyzes the behavior of individuals who must take preventive measures to protect their own health in a context of uncertainty. On the other hand, it is devoted to an empirical study to identify the perceptions and information that individuals have in terms of health risk. In addition, throughout this work, we have sought to study the relevance of the theoretical model developed with regard to the policies practiced. The first chapter presents the principles for modelling economic decisions in the presence of a more or less well known health risk. After detailing the different approaches in models of decisions under risk and uncertainty, we highlight the importance of introducing two-dimensional (or multidimensional) variables into the choice model to allow for the multidimensional environment of health risks. The second chapter is an original study proposed on the analysis of health prevention when individuals are ambiguity averse. In this chapter, we studied individual prevention behaviors in the face of health status uncertainty and showed that ambiguity aversion induces individuals to do more primary and secondary prevention under the assumption of increasing marginal utility of wealth with health status. (.).