Léa MARCHAL, Guzmán OURENS, Giulia SABBADINI
When Immigrants Meet Exporters: A Reassessment of the Migrant-Native Wage Gap ~ Submitted.

We show that high-skilled immigrants earn higher wages than comparable natives in exporting firms, while low-skilled immigrants do not. Using matched employer–employee and customs data from Portugal, we document a reversal of the migrant-native wage gap among high-skilled workers in exporting firms. We develop a model with heterogeneous firms and directed search, in which high-skilled immigrants lower export costs through destination-specific knowledge. The model yields an information premium that explains the wage gap reversal. We provide evidence consistent with this mechanism using information on the origin country of the workers and the destination country of the firm’s exports. Our results identify a novel channel through which trade reduces wage inequality conditional on the skill level and origin country of the employees, and provide new micro-level evidence on the role of workers in shaping firm-level internationalisation.
DICE Discussion Paper (2025) New!
CES Working Paper (2023) (using French data)

Clément NEDONCELLE, Léa MARCHAL, Amandine AUBRY, Jérôme HÉRICOURT
The names of the authors appear in random order.
Does Immigration Affect Native Wages? A Meta-Analysis ~ R&R at Labour Economics

The impact of immigration on native workers’ wages has been a long-standing debate in labour economics. This meta-analysis synthesises findings from 88 studies published between 1985 and 2023, providing a comprehensive assessment of reduced-form estimates of the wage effect of immigration. Our results align with the existing literature, showing that the average wage effect is centred around zero, with substantial heterogeneity across studies. We highlight the critical role of contexts and methodological choices in shaping wage estimates. In particular, we find that shift-share instrumental variables correct for an upward bias of the OLS. Our findings emphasise the need for replication studies and greater transparency in methodological choices.
CES Working Paper (2025) ~ CEPII Working Paper (2025) ~ New!

Léa MARCHAL, Claire NAIDITCH, Betül SIMSEK
Aid as a Migration Policy Tool ~ submitted

Foreign aid is often promoted as a way to curb emigration by improving welfare in countries of origin. However, the effectiveness of such a policy remains debated. To contribute to this debate, we develop a random utility maximisation model yielding a gravity equation, which we estimate using OECD migration and aid data for 2011-2019. We exploit the differences between bilateral aid and multilateral aid, for which donors are masked, to isolate the donor-specific and non-donor-specific effects of aid on migration. We show that aid increases rather than reduces migration. The donor-specific channel plays a dominant role in explaining this positive effect, which is primarily conveyed through an information channel.
Draft available upon request.

Léa MARCHAL, Claire NAIDITCH, Martin VALDEZ, Adnan SERIC
Unleashing Potential: Foreign Workers and Direct Exports

This paper studies how skilled foreign workers affect firms’ export mode. We build a model with heterogeneous firms, incorporating trade intermediaries and foreign workers, and analyse how these workers affect firms’ choice to export directly, indirectly or not at all. We show that foreign workers help firms relax productivity constraints to export, both directly and indirectly. This pro-trade effect is larger for highly productive firms that export directly. Using the 2010 UNIDO Viet Nam Investor Survey, we find evidence of the pro-trade effect of skilled foreign workers and their asymmetric impact across firms of different sizes.
LEM Working Paper (2023) ~ New version using Portuguese data available soon.

Farida ABDELSALAM, Léa MARCHAL, Frauke STEGLICH
Human Rights Due Diligence and Trade: Evidence from the French Duty of Vigilance Law

Although participation in global value chains (GVCs) is widely associated with economic benefits, the sustainability of production in GVCs is increasingly controversial. As a result, several industrialized countries have introduced laws on human rights due diligence (HRDD) that mandate companies to ensure specific minimum standards for themselves and the suppliers along their value chains. Some fear that less developed countries might be displaced from global supply chains and that, thus, the goal of improving working conditions and environmental outcomes in developing countries might be missed. In this paper, we use the French HRDD legislation to analyze the impacts of such laws on firms’ trading strategies, especially with developing countries. Using French firm-customs data and a difference-in-difference approach, we explore the risk of trade diversion – the shift from high-risk to relatively low-risk trading partners regarding the risk of negative social and environmental externalities. In so doing, we explore sector, country, and relationship-specific heterogeneity and consider differences in firms’ exposure to human rights risks in their supply chains. Preliminary findings indicate no overall change in imports but a drop in imports and a reduction in the number of import markets from less developed countries.
Work in progress. Draft available soon.