Pierre Rousseaux

I am a third-year PhD candidate at CREST (École Polytechnique, ENSAE), supervised by Prof. Roland Rathelot and Prof. Arne Uhlendorff. I am also a research affiliate at the IPP (CREST-PSE), where I spent my first PhD year as a research economist in its labour market division, and a research associate at the i-MIP (PSE).

From February to June 2026, I will be visiting the LSE Economics Department, invited by Prof. Camille Landais.

My research focuses on labour economics and policy evaluation, with a focus on job search behaviour, unemployment insurance, and information frictions in hiring. I also work on trade economics topics, especially the identification and analysis of trade dependencies.

Incoming presentations: LSE Applied Economics seminar (02/2026), LSE Public internal seminar (02/2026), DG Grow Research conference on the EU Single Market (03/2026)

Contact me by mail pierre.rousseaux@ensae.fr or follow my research and activities on:

New publications

"Réforme du salaire journalier de référence et trajectoires professionnelles", 2025, with Fontaine, F. and M. To, in Rapport du comité d’évaluation de la réforme de l’assurance chômage 2019-2021, French Ministry of Labor [Paper] [Summary]

Abstract: This study evaluates the impact of the October 2021 reform to the French unemployment insurance system, which modified the computation of the daily reference wage. The reform reduced daily benefit amounts (0-10%) while extending potential benefit duration (up to +75%) for job seekers with fragmented careers (alternating periods of employment and non-employment). Using a difference-in-differences approach on administrative data, we exploit heterogeneity in exposure - measured by the share of non-employment time during the reference period. For the most affected individuals (50%+ non-employment), the reform lowered benefit levels, extended entitlements, and led to a 5-20% increase in employment days in the six months post-unemployment. Employment-to-benefit elasticities range from -0.5 to -0.9. The reform reduced UI take-up by 2pp but had no effect on contract type, wage, or mobility. It did not trigger substitution toward welfare transfers (e.g. RSA), limiting fiscal impact to the UI system. Among UI recipients, cumulative benefits declined by up to €1,000 over six months.

VR n°16_réforme assurance chômage_SJR et trajectoires pro_synthèse.pdf

Check here to see a page dedicated to trade vulnerabilities (methodologies, EU analysis, EU-country analysis)

A review of EU trade dependencies, 2025, in the EIB (European Investment Bank) flagship investment report 2024/2025 [Box] [Report]

Abstract: This contribution analyzes EU trade vulnerabilities since 2002 by identifying critical imported products and their role in value chains. Using the European Commission’s method combined with Mejean and Rousseaux (2024), it documents increasing reliance on specific suppliers - especially China - while dependencies on the US and other countries have declined. The most critical products lie upstream, with 49% more than three stages from final use, amplifying the impact of disruptions. Vulnerabilities are concentrated in strategic sectors like chemicals, metals, and ceramics, and persist over time: 41% of those seen pre-crisis remained just after, and 35% in later periods. While some concern low-risk consumer goods, others involve essential industrial inputs with systemic risks. The study calls for a balanced resilience strategy, combining diversification, local production, and industrial coordination to secure supply chains without undermining trade efficiency.

Evolution of trade dependencies imported by the EU27 between 2002 and 2022, by methodologies.

Source: EIB Investment Report 2024/2025, Chapter 5, Box C (P. Rousseaux)

Identifying European trade dependencies, 2024, with I. Mejean; in Pisani-Ferry, J, B Weder Di Mauro and J Zettelmeyer (eds), Paris Report 2: Europe's Economic Security, CEPR Press, Paris & London [Paper] [Report]

CEPR Bruegel Paris Report, Reports webpage, CEPR's Paris Symposium 2023

Media: Bruegel's podcast, VOXeu Column, CRESTive Columns, France Culture

Seminar: CEPII-Banque de France Competitiveness Seminar, Franco-German Fiscal Policy Seminar

Abstract: We review and extend upon existing literature using product-level trade data to identify trade dependencies that expose the European Union to potential disruptions. While acknowledging the significance of concentrated foreign input sourcing as a source of vulnerability, a comprehensive assessment of vulnerabilities should also consider the potential for substituting away from disrupted input sources, both domestically and abroad. This may necessitate devising novel statistical measures at the European level. We present a novel methodology that identifies trade dependencies by integrating these substitution sources. Our review encompasses normative arguments justifying public interventions to improve the resilience of value chains. We intersect our identified dependencies with a measure of geopolitical risk, their upstreamness in the value chain, and also focus on critical products and strategic green technologies. The specific targeting of these policies varies depending on the nature of risks they aim to mitigate. Finally, we discuss the range of policy tools available for crafting a resilience policy.