Publications des chercheurs de PSE

Does democracy help Kenyan citizens to struggle against the HIV epidemic? Yet, very little attention has been devoted to establish whether political regimes react differently to the HIV infection. Using an electoral definition of democracy makes a contribution in understanding which aspects of political rules matter to manage the disease. Using a difference-in-difference design that draws upon pre-existing variations in HIV intensity and cohort's exposure to democracy, we find that a person living under democracy is less likely to have a HIV infection. Further, we present some evidence of ethnic favoritism and gender disparities during periods of non-democracy.

This article examines the influence of malaria on human capital accumulation in the village of Diankabou in Mali. To account for malaria endogeneity and its interaction with unobservable risk factors, we exploit natural variations in malaria immunity across individuals of several sympatric ethnic groups—the Fulani and the non-Fulani—who differ in their susceptibility to malaria. The Fulani are known to be less susceptible to malaria infections, despite living with a similar malaria transmission intensity to those seen among other ethnic groups. We also use natural variation of malaria intensity in the area (during and after the malaria transmission season) and utilise this seasonal change as a treatment. We found that malaria has an impact on cognitive and educational outcomes in this village.

We estimate the effects of a large-scale anti-malaria campaign on a rich set of human capital outcomes in 27 Sub-Saharan African countries. Using pre-campaign malaria risk as treatment probability, we exploit quasi-experimental variation in period and cohort exposure to anti-malaria campaigns. A conservative interpretation of our results shows a globally positive impact malaria aid: campaigns reduced the probability of infant mortality (1 percentage point) and birth (0.4 p.p.) and increased educational attainment (0.4 years) and the likelihood of adult paid employment (6 p.p.). These findings demonstrate how the effects of sweeping disease reduction efforts extend beyond health outcomes.

We provide one of the first formalizations of a vaccination campaign in a decisiontheoretic framework. We analyse a model where an ambiguity-averse individual must decide how much effort to invest into prevention in the context of a rampant disease. We study how ambiguity aversion affects the effort and the estimation of the vaccine efficacy in clinical trials and immunization campaigns. We find that the behaviours of individuals participating in a clinical trial differ from individuals not participating. Individuals who are more optimistic toward vaccination participate more in trials. Their behaviours and efforts are also affected. As a result, because vaccine efficacy depends on unobserved behaviours and efforts, the biological effect of the vaccine becomes difficult to evaluate. During the scale-up phase of a vaccination campaign, provided that vaccine efficacy is established, we show that vaccine hesitancy may still be rational.

Background: Influenza mortality has dramatically decreased in France since the 1950s. Annual death rates peaked during two pandemics: the Asian flu (1956–1957) and the Hong Kong flu (1969–1970). Objective: This study’s objective is to evaluate whether the second pandemic created a structural change in the dynamics of influenza mortality in France. Methods: We employ a new database on influenza mortality since 1950 at the subnational level (90 geographic areas) to estimate statistical models to find out whether a structural change happened and to explain the differences in mortality rates across geographic areas. Influenza mortality increased between 1950 and 1969 and decreased from 1970 onward. Conclusions: The Hong Kong flu is identified as the event of a structural break. After the break, geographical differences are less explained by regional characteristics such as income, density, or aging ratio. The Hong Kong flu was found to be associated with a major change in influenza mortality in France. Change in health practices and policies induced a decline in mortality that started in 1970, just after the pandemic. The health benefits are notably important for senior citizens and for the poorest regions. Contribution: We employ a new database on influenza mortality since 1950 at the subnational level (90 geographic areas). Change in health practices and policies induced a decline in mortality that started in 1970, just after the pandemics. The health benefits are notably important for senior citizens and for the poorest regions.

Influenza mortality has dramatically decreased in France since the 1950s. Annual death rates peaked during two pandemics: the Asian flu (1956-57) and the Hong-Kong flu (1969-1970). This study’s objective is to evaluate whether the second pandemic created a structural change in the dynamics of influenza mortality in France. We employ a new database on influenza mortality since 1950 at the subnational level (90 geographic areas) to estimate statistical models to find whether a structural change happened and to explain the differences in mortality rates across geographic areas. Influenza mortality increased between 1950 and 1969, and decreased from 1970 onward. The Hong-Kong flu is identified as the event of a structural break. After the break, geographical differences are less explained by regional characteristics such as income, density or aging ratio. Hong Kong flu was found to be associated with a major change in influenza mortality in France. Change in health practices and policies induced a decline in mortality that started in 1970, just after the pandemics. The health benefits are notably important for senior citizens and for the poorest regions.

We provide one of the first formalizations of a vaccination campaign in a decisiontheoretic framework. We analyse a model where an ambiguity-averse individual must decide how much effort to invest into prevention in the context of a rampant disease. We study how ambiguity aversion affects the effort and the estimation of the vaccine efficacy in clinical trials and immunization campaigns. We find that the behaviours of individuals participating in a clinical trial differ from individuals not participating. Individuals who are more optimistic toward vaccination participate more in trials. Their behaviours and efforts are also affected. As a result, because vaccine efficacy depends on unobserved behaviours and efforts, the biological effect of the vaccine becomes difficult to evaluate. During the scale-up phase of a vaccination campaign, provided that vaccine efficacy is established, we show that vaccine hesitancy may still be rational.

Many recent studies show that Europe has had a lower mortality inequality for most ages than the United States over the last thirty years. However, the evolution of the income gradient in mortality all along the twentieth century remains poorly understood. This article uses a unique dataset that gives the annual lifetables and fiscal income for the 90 administrative regions of mainland France from 1922 to 2020. The income gradients in mortality are computed across regions using a traditional method with calendar ages and, alternatively, with mortality milestones to control for the increase in life expectancy over time. The study reveals a systematic reversal of the gradient that occurred around the 1970s for both sexes and all ages or mortality groups when calculated at an aggregated level. Inequality in mortality amongst the oldest age groups has however returned to a level observed at least ten years earlier because of Covid-19, even after controlling for mortality improvements over the period.