Research
Working Papers
- Wages, Agglomeration and Air Pollution (draft available upon request)
Abstract
Denser cities are more productive and offer higher wages, through agglomeration externalities. But urban density may also bring about higher local air pollution, which can either be compensated for via higher wages (as a consumption disamenity), or have negative productivity effects, leading to lower wages (as a production disamenity). This paper studies how air pollution affects wages across French cities, and whether it enhances, or instead attenuates, nominal wage differentials (the urban wage premium) and real wage differentials. Using panel data over the 2002-2018 period and a double instrumental variable strategy to tackle endogeneity concerns, I first confirm that density does foster fine particulate matter (PM2.5) concentration. Then, I show that as wages react negatively, nominal wage gains from agglomeration are lower on average due to local air pollution. Interestingly, real wages also negatively affected. Relying on the structure of a spatial equilibrium model, I show that this is because local air pollution is an even stronger production disamenity than it is a consumption disamenity: while PM2.5 impairs productivity even at low levels, compensation only kicks in for the largest, most polluted cities. There is also heterogeneity by skill, as high-skill workers receive a larger compensation for air pollution than low-skill ones.Next presentation EAYE 2025 at King’s College London, 29-31 May 2025
- Disparities in Recent Air Quality Improvements Across and Within French Cities (draft available upon request)
Abstract
I make use of high-resolution remote-sensing data to provide the first national-scale study of cross-sectional and longitudinal inequality in exposure to fine particulate matter (PM2.5) in France, focusing on neighbourhood income and the share of immigrants. There is a U-shaped relationship between income and PM2.5 exposure at the national level, but within urban areas, poorer neighbourhoods are more exposed on average. I also document that holding income constant, neighbourhoods with a high share of immigrants are overexposed. In a second step, I exploit a change in air quality schemes at the level of urban areas in a staggered adoption event-study framework, so as to shed light on potentially unequal benefits from the induced reduction in exposure. Results suggest that the adoption of new air quality schemes accounted for about 30\% of the total change in air pollution over the period. Neighbourhoods with a higher share of immigrants did not experience a significantly larger decrease in PM2.5, contributing to a stagnation in disparities in exposure. Suburbs received larger improvements than city centres. I highlight which types of measures proved most effective, by targeted sector.Next presentation 5th Discrimination and Diversity Workshop organised by University of Exeter (online), 2-3 June 2025
Work in Progress
- Commuting, Air Quality and Welfare, with Pol Cosentino (Paris 1, CES)
We study the impact of both existing and planned public transport infrastructure investments on local air quality and welfare, focusing on the Paris region. We start by providing reduced-form evidence that the creation of new tramway lines in the 2010s triggered an increase in public transport usage, thus improving local air quality. We then proceed to extend the now standard quantitative urban structural model (QSM) of a city with endogenous amenities and productivity, to include a) transport choice between a polluting and a non-polluting option, and b) local air pollution that affects both amenities and productivity. We calibrate the model to 2018 neighbourhood-level data for Paris, and use it to perform two main prospective counterfactual analyses: the first, on the largest public transport infrastructure Paris has built since the 1960s and which is yet to be delivered, the \textit{Grand Paris Express} metro project, and the second, on smaller-scale tramway line investments. We find welfare gains of 1 to 2\%, and highlight the critical role of local air pollution as a negative externality, which is reinforced by in-migration. These results suggest that standard QSMs tend to underestimate the effect of new public transport infrastructure by omitting air quality improvements. %Interestingly, we find mixed effects on air quality: due to the clustering of jobs close to new metro stations, residents from unconnected neighbourhoods drive longer distances by car, thus locally increasing air pollution, which decreases elsewhere.
First presentation! EEA Annual Congress in Bordeaux, 25-28 August 2025
- Place-Based Interventions and Environmental Inequalities