Working Papers

La filière automobile en France entre 2010 et 2023: Anatomie d'une chute with Hugo Camille and Swann Chelly , 2026

[4-pages summary in French]

[+] Abstract : Entre 2010 et 2023, l'emploi chez les constructeurs automobiles a baissé de 35%, alors qu'il stagne dans le reste de l'industrie manufacturière. Nous documentons la baisse concomitante chez les fournisseurs industriels des constructeurs automobiles à l'aide de deux enquêtes sur les sociétés de la filière, en 2010 et 2023. Sous l'effet conjugué des cessations d'activité, de sorties de la filière et de réductions d'effectifs dans les sociétés restées actives dans la filière, l'emploi parmi les fournisseurs industriels a chuté de 32%. Cette baisse concerne presque tous les territoires et est uniforme sur l'ensemble des métiers. Les fournisseurs dont l'activité dépend le plus de l'automobile voient leur emploi chuter plus sévèrement entre 2010 et 2023 et présentent un risque accru de fermeture sur la période. Leur capacité à se diversifier vers d'autres marchés est restée limitée, particulièrement pour les plus exposés aux constructeurs. Au cours des années 2000, un nombre important de fournisseurs s'est mis à exporter vers les pays qui accueillent les usines des principaux constructeurs français. Mais entre 2010 et 2023 cette dynamique ne se poursuit pas et les fournisseurs ouvrent peu de filiales dans ces pays. Enfin, une grande partie des fournisseurs a déjà intégré la chaîne de valeur des véhicules électriques, même si près d'un tiers des sociétés dépend encore uniquement de la production de véhicules thermiques.

State-Dependent Pass-Through with Heterogeneous Exposure to Common Shocks with Julien Martin and Isabelle Mejean , 2026

[New CEPR Discussion Paper 21156] [Old CEPR Discussion Paper 18596] [CAE Focus]

[+] Abstract : We study state-dependent cost pass-through using the recent surge in energy prices as a natural experiment. Our empirical analysis combines firm-level measures of exposure to energy cost shocks with firm- and product-level output prices from the French Producer Price Index (PPI). We find that pass-through increased from about 70% in the pre-crisis period to nearly full pass-through in 2021–2022, and is significantly higher among the most exposed firms. We develop a state-dependent pricing model in the spirit of Cavallo et al. (2023), augmented with heterogeneous exposure to energy shocks, which quantitatively rationalizes these patterns. The model shows how heterogeneity in firms’ exposure to common shocks shapes the aggregate response of prices to supply disturbances.

Inventories, Diversification, and Trade Vulnerabilities , 2025

[VoxEU] [4-pages summary in French]

[+] Abstract : To reduce their exposure to supply-chain risk, firms commonly rely on two strategies: input stockpiling and diversification of supply sources. This paper presents new evidence on how French manufacturing firms used inventories and diversified their country-specific supply risks between 2012 and 2023. The use of these strategies varies widely: large firms are generally more diversified and maintain lower inventories relative to smaller firms. Overall, firms that diversify more tend to stockpile less, even conditional on firm size. Diversification is also linked to lower import volatility. Together, these patterns suggest that inventories act as a buffer when firms are unable to reduce risk through diversification. These insights matter for assessing trade vulnerabilities: products sourced from few countries may appear exposed to risk, yet in practice they are often imported by firms holding large stocks. Accounting for inventories can halve the number of products considered highly vulnerable.

Ambient Density and Urban Crime: Evidence from Smartphone Data with Vincent Rollet , 2025

[Slides]

[+] Abstract : Ambient density --- the number of people in a given area at a given time --- is often hypothesized to be an important determinant of urban safety. However, there has been limited empirical evidence to support this claim due to the difficulty of measuring the movement of ordinary citizens. With smartphone location data, we measure ambient density in Chicago neighborhoods and estimate its effect on crime rates. Using a shift-share instrument and temporary transit station closures for identification, we show that crime rates fall when ambient density increases. We find that the beneficial effects of density are strongest in low and medium-density neighborhoods, which suggests that policies spreading people over space are likely to reduce crime. Finally, we show how the development of work-from-home is likely to affect crime rates in different neighborhoods of Chicago.

Work in Progress

Spatial Comovements with Swann Chelly and Isabelle Mejean

[+] Abstract : We investigate how industrial specialization and production networks shape local business cycle fluctuations. Using detailed plant-level sales data from two major French manufacturing sectors over 2011–2019, matched with firm-level production linkages, we first document that: i) The spatial organization of production in France displays significant industrial clusters, including in the focal aerospace and car industries, ii) production linkages in these sectors are spatially concentrated, and iii) these local production networks generate comovements along the value chains that amplify local business cycles. Using a structural model estimated from the micro-level data, we quantify the diffusion of demand shocks to the aerospace and car industries over space through input-output networks. Exogenous shocks to these sectors spillover to upstream industries, generating sizable local business cycles.

Publications

Reorganizing Global Supply-Chains: Who, What, How, and Where with Gabriel Baratte and Lionel Fontagné , Journal of Economic Behavior and Organization 237, September 2025

[Banque de France Working Paper n969] [Insee Working Paper n2024-24] [4-pages summary in French]

[+] Abstract : In an increasingly uncertain environment, firms are differently exposed to shocks and may or may not bear the cost of reorganizing their value chain by reshoring or offshoring. This paper draws on a survey of French firms about the decision to reorganize part of their value chain between January 2018 and December 2020. Reorganizations prove to be infrequent, made by firms employing a higher proportion of skilled workers, in manufacturing rather than in services, with a predominance of multinational firms. Even though high-skill firms are reorganizing more, reorganized business functions are less skill-intensive and more intensive in routine tasks. Activities more intensive in intangible capital are more likely to be reorganized within firm's boundaries. Last, besides reshoring in France, activities are located close to France when offshored. India, combining low-average wage and a large endowment of high-skilled workers, receives a disproportionate share of skill-intensive activities.

Supply Shocks in Supply Chains: Evidence from the Early Lockdown in China with Julien Martin and Isabelle Mejean , IMF Economic Review 71(1): 170--215, 2023

[CEPR Discussion Paper 16813] [VoxEU] [4-pages summary in French] [Video at IMF ARC (44:30)]

[+] Abstract : How do firms in global value chains react to input shortages? We examine micro-level adjustments to supply chain shocks, building on the COVID-19 pandemic as a case study. French firms sourcing inputs from China just before the early lockdown in the country experienced a relative drop in imports that increases from February to April 2020. This shock on input purchases transmits to the rest of the supply chain through exposed firms' domestic and export sales. Between February and June, firms exposed to the Chinese early lockdown experienced a 5.5% drop in domestic sales and a 5% drop in exports, in relative terms with respect to comparable non-exposed firms. The drop in foreign sales is entirely attributable to a lower volume of exports driven by a temporary withdrawal from occasional markets. We then dig into the heterogeneity of the transmission across treated firms. Whereas the ex-ante geographic diversification of inputs does not seem to mitigate the impact of the shock, firms with relatively high inventories have been able to absorb the supply shock better.