CREST Working Papers Series No. 2025-13
by Marion Brouard and Léa Dubreuil
DP20620 Flexclusivity: Exclusive Agreements with Competitive Flexibility – Philippe Choné, Laurent Linnemer – 4 Sep 2025
DP20618 Wage Markdowns and the Sorting of Workers to Firms when Skills are Bundled – Philippe Choné Francis Kramarz Oskar Nordström Skans – 4 Sep 2025
DP20492 Escaping Labor Scarcity: Innovation and Human Capital after WW1 in France – Antonin Bergeaud Jean-Baptiste Chaniot Clément Malgouyres – 26 Jul 2025
China: are air conditioners at odds with climate ambitions?
Patricia Crifo develops the question of air conditioners in China for Polytechnique Insights.
17/09/2025
A New Academic Year, New Faces at CREST
Every year, CREST welcomes a new cohort of researchers who bring fresh perspectives, curiosity, and energy to our community. This fall, we are pleased to host new researchers, postdoctoral fellow, PhD students, and visiting researchers from around the world.
Their arrival marks an important moment in the life of our lab: the opportunity to grow, to renew dialogues across disciplines, and to continue building a vibrant and diverse research environment. Whether they join us for a few months or several years, these newcomers contribute to the intellectual richness and collaborative spirit that define CREST.
We are pleased to introduce the researchers who are joining CREST this year, each bringing their unique background and expertise to our four research areas: economics, sociology, statistics, and finance-insurance.
Researchers
This year, several new researchers are joining CREST, strengthening our core faculty and bringing new perspectives across ou disciplines.
Philippe Coulangeon is a CNRS Research Director, affiliated with the Centre for Research on Social Inequalities (CRIS) at SciencesPo Paris.
His work is set at the intersection of cultural sociology and social inequalities. He explores the stratification of cultural practices and tastes, the dynamics of mass versus elite culture, artistic professions, and the democratization of culture. More recently, he has integrated environmental concerns into his analysis.
Fanny Landaud is a CNRS researcher from CY Cergy Paris University and she is an IZA Research Fellow since 2019.
Her research covers applied microeconomics – particularly labor, education, family, and health economics – with a focus on the determinants and consequences of socioeconomic and gender inequalities in education and the labor market.
Antonio Ocello was a Postdoctoral Researcher in Statistics and Machine Learning at École polytechnique (CMAP) since 2023.
His research focuses on mean-field games and mean-field control problems, branching diffusion processes, and stochastic optimal control, combining advanced probabilistic methods with applications in machine learning. He has contributed to work on convergence bounds for trust-region policy optimization in mean-field games and is developing stochastic target frameworks for branching processes.
Enrico Ruolino was a Senior Researcher at the University of Lausanne.
His work focuses on public and labor economics, with a particular emphasis on behavioral responses to tax policy, gender inequality, intergenerational mobility, and educational outcomes.
Clémentine Van Effenterre was previously an Assistant Professor of Economics at the University of Toronto.
Her research lies at the intersection of labor economics, applied microeconomics, and political economy. Notably, she investigates how norms, institutions, and policies shape labor market outcomes – examining issues like maternal labor supply, gender gaps in science and tech, and how having daughters influences political attitudes. She also hosts the “InequaliTalks” podcast on economics and inequality.
Postdoctoral Fellows
Our new postdoctoral researchers are contributing to ongoing projects and launching their own work in close collaboration with CREST teams.
Stéphane Lhaut, in the Finance-Insurance team, with Caroline Hillairet and Olivier Lopez.
Angelica Martinez-Leyva, in the Economics cluster at CREST-ENSAI, with Marion Goussé
Andrea Pandolfi, in Statistics, with Nicolas Chopin
Arthur Stephanovitch, in Statistics, with Austin Stromme
Lishu Zhang, in the Finance-Insurance team, with Olivier-David Zerbib
PhD Students
This year, we welcome a new cohort of PhD students who are beginning their research journeys within our vibrant academic community.
30 new PhD students are joining our laboratory in our different research clusters.
9 PhD students will join our Economic team, 7 in the Finance-Insurance cluster, 12 new PhD students in Statistics, and 2 in our Sociology team.
4 of them will join our lab on the CREST-ENSAI campus in Bruz while the remaining PhD students will join our CREST-ENSAE Paris campus in Palaiseau.
This new team will also be joined by 3 PhD students in ATER contracts in the CREST-ENSAI campus.
Visiting Researchers
CREST is also hosting several visiting researchers this year, joining us for research stays that foster international collaboration.
Yang Chen (Lausanne University, Switzerland) is joining our Economic team to work with Julien Combe on Microeconomic theory and matching theory.
Matias Ortiz (Universidad de Chile, Chile) will work with Vianney Perchet on Learning-Augmented Online Algorithms for Matroid-Constrained problems under Partial in our Statistical team.
Simon Luck (Universita di Bologna, Italy) is joining Etienne Ollion’s team in Sociology to work on using natural language processing to study the relevance of the news media for political representation and decision-making processes.
Jules Verin (ENS Lyon, France) will work with Bertrand Garbinti in Economics on Wealth Accumulation, Life Cycle, and Taxation.
Väinö Yrjänäinen (Uppsala University, Sweden) is joining the Sociology team with Etienne Ollion to work on using work embeddings and transformer models in computational social sciences.
L’IA générative est-elle un gain pour la recherche ?
Bayesian Bi-level Sparse Group Regressions for Macroeconomic Density Forecasting
CREST Working Papers Series No. 2025-12
by Matteo Mogliani and Anna Simoni
Do Billionaires Pay Taxes?
CREST Working Papers Series No. 2025-11
by Laurent Bach, Antoine Bozio, Arthur Guillouzouic and Clément Malgouyres
Summer School on Environmental Data Collection and Analysis for the Social Sciences
From June 2 to 6, 2025, the Energy4Climate (E4C) Interdisciplinary Center and CREST brought together 20 participants for a Summer School on Environmental Data Collection and Analysis for the Social Sciences.
Over the course of one week, participants took part in lectures, workshops, and group activities designed to strengthen their skills and foster collaboration. A special highlight of this edition was the opportunity to join shared sessions with Columbia University, made possible through the Alliance partnership. These exchanges created a unique space for dialogue between institutions and disciplines, all centered on the challenges of climate and energy transitions.
This Summer School was made possible thanks to the generous support of the Fondation de l’École polytechnique and the Fonds Ifker pour le Climat. Their commitment played a key role in making the program accessible and impactful for the next generation of researchers.
We extend our warm thanks to all speakers and participants who contributed to the success of this edition.
Relive the Summer School experience and hear directly from participants in the video below