• Maël’s presentation :

Title : Who bears the environmental cost of urban agglomeration?

Abstract : This article investigates the effects of urban agglomeration on inequalities in exposure to air pollution in France. Using detailed data at a very fine scale on income and air pollution, the study finds that greater urban agglomeration increases the likelihood of poorer households being more exposed than wealthier households to PM2.5, PM10 and  NO2. In contrast, urban agglomeration decreases the probability of poorer households being more exposed than wealthier households to O3. These findings are robust to instrumental variable techniques, employing historical population density and a novel instrument based on World War I fatality rates. The disparities may partially be explained by wealthier households relocating from city centers to suburban areas as urban agglomeration increases, thereby avoiding city-center pollutants while encountering suburban pollutants. This research highlights how urban agglomeration shapes environmental inequities, demonstrating that the most disadvantaged urban populations tend to bear a disproportionate burden of environmental congestion costs.

• Richard’s presentation :

Title : Biodiversity conservation to reduce conflicts ?

Abstract :  We investigate the impact of biodiversity on conflict in Africa, with a particular interest in the mechanism of air pollution. The unit of our analysis is cells of 0.1 × 0.1 degrees latitude and longitude (approximately 11 km × 11 km at the equator). Using spatial data on conflict events, tree cover, deforestation, NDVI, and fine particulate matter over the period 2000–2023, we show that biodiversity reduces conflict by improving mental health through the mitigation of air pollution’s negative effects. We use an excludable instrument to test the effect of pollution on conflict. The results show that wind speed influences air pollution without having a direct impact on conflict.

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