Sébastien Willis

I am an applied microeconomist, specialising in labour and development economics. My work focuses in particular on the labour market outcomes of migrants in developed and developing countries.

I am currently a postdoctoral researcher in the Department of Economics at Uppsala University and research coordinator for the Uppsala Immigration Lab. I received my PhD in Economics from Universitat Pompeu Fabra.


Email: sebastien.willis [at] nek.uu.se  /  Curriculum Vitae



Working papers

The dynamics of ethnic segregation in the German labour market
Submitted

This paper uses administrative data on German firms to empirically study the dynamics of workplace segregation between 1975 and 2019. Building on the literature on neighbourhood segregation, the analysis tests for the presence of tipping points in the composition by nativity of firms. The evidence of tipping points is limited, and is strongest for firms in relatively low-skill sectors, including Manufacturing or Hotels and restaurants, and during years of high immigrant inflows, particularly 1990–1995 and 2013–2018. Furthermore, descriptive evidence shows that segregation in a given cohort of firms generally declines over time, only increasing when there is a large immigrant inflow. These findings suggest that the preferences of workers over the composition of their workplaces are not likely to be the main cause of observed workplace segregation.

Workplace segregation and the labour market performance of immigrants
CESifo Working Paper No. 9895, submitted

This paper studies the effect of conational coworkers in an immigrant’s first job on subsequent labour market outcomes using German register data. I instrument for the conational share using hiring trends in the local labour market and find that a ten-percentage-point increase in the initial conational share lowers employment rates by 3.2 percentage points in the long term, an effect not observed for non-conational immigrants, with no effect on wages in the long term, conditional on employment. Descriptive evidence suggests that the employment effect is due both to differential host country-specific human capital accumulation, as well as changes in job search behaviour induced by denser conational networks.



Work in progress

Social networks and the labour market assimilation of immigrants
with Olof Åslund and Mattias Engdahl

It's who you know: Homophily and the heterogenous value of professional connections