Thomas Peyrat, PhD student at CREST-GENES and at Exiom Partners, in Finance-Insurance, has just reached a major milestone in his doctoral journey with the publication of his first paper in ESAIM: Probability and Statistics, as well as the release of a new working paper.
These two works, conducted in collaboration with his advisors Caroline Hillairet (ENSAE Paris – CREST) and Anthony Réveillac (INSA Toulouse – Toulouse Mathematics Institute), are part of his PhD carried out in partnership with Exiom Partners, a consulting firm actively involved in applied research.
🔹 A new Clark–Ocone formula for Poisson functionals
The first paper, titled A non-compensated Clark–Ocone formula for Poisson functionals, develops a decomposition formula for integrable Poisson functionals. This non-compensated version offers several technical advantages compared to the classical compensated approach, paving the way for new potential applications.
👉 Read the article in ESAIM: Probability and Statistics
🔹 Multivariate self-exciting processes with dependencies
The second work, currently available as a preprint, introduces a new class of multivariate self-exciting processes capable of modeling dependencies between event intensities and values. This modeling framework is particularly promising in insurance applications, for instance to capture links between claim frequency and severity.
👉 Read the preprint
We warmly congratulate Thomas for these important contributions, which highlight the strength of collaboration between academic research and industry, as well as the quality of doctoral training at CREST.
Contribution de Pierre Rousseaux à l’Investment Report 2024/2025 de la European Investment Bank (EIB)
Pierre Rousseaux, doctorant au CREST-GENES, signe une contribution dans l’Investment Report 2024/2025 de la Banque Européenne d’Investissement (BEI) (Encadré C, Chapitre 5).
Dans un contexte de tensions géopolitiques croissantes, les dépendances commerciales de l’Union européenne deviennent un enjeu stratégique majeur. La guerre en Ukraine, la montée du protectionnisme aux États-Unis et la concentration des chaînes de valeur en Chine exposent l’UE à des risques accrus de perturbations d’approvisionnement. Quels sont les produits et secteurs les plus vulnérables ? Quelles sont les dépendances critiques ? Comment renforcer la résilience européenne ?
Dans cette contribution, Pierre Rousseaux explore ces questions sur une période plus étendue que celle abordée dans son précédent travail coécrit avec Isabelle Méjean pour le CEPR – Centre for Economic Policy Research. Voici les principales conclusions issues de son analyse pour la BEI :
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Les vulnérabilités sont de plus en plus concentrées sur les importations chinoises
La part de la Chine dans les dépendances commerciales de l’UE a significativement augmenté, tandis que celle des États-Unis et du reste du monde a diminué de 3 à 10 points de pourcentage. -
Les dépendances en amont des chaînes de valeur sont les plus risquées
Les vulnérabilités situées à plus de trois étapes du consommateur final représentent 49 % des produits critiques. Une rupture dans ces segments pourrait affecter l’ensemble des chaînes d’approvisionnement européennes. -
Certaines dépendances sont structurellement critiques pour l’industrie européenne
Les produits vulnérables se concentrent dans les secteurs de la chimie, des métaux et de la céramique — industries essentielles pour de nombreuses filières stratégiques. -
Ces vulnérabilités sont persistantes
41 % des dépendances commerciales identifiées avant la crise financière mondiale étaient encore présentes après celle-ci, et 35 % ont perduré à long terme, témoignant de leur caractère structurel et de la difficulté à s’en détacher. -
Sur les 5 381 produits importés par l’UE, le nombre de vulnérabilités identifiées varie selon les critères retenus : entre 359 (avec les critères les plus larges) et 29 (selon les cinq critères les plus restrictifs définis avec Isabelle Méjean). Bien que ce chiffre puisse sembler faible, il regroupe des produits à risque extrême, caractérisés par :
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une forte concentration des fournisseurs hors UE
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une très faible production au sein de l’UE
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une capacité de substitution quasi inexistante en cas de choc
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Pourquoi est-ce crucial ?
Identifier précisément les dépendances et leurs risques permet de concevoir des politiques ciblées : diversification des fournisseurs, relocalisation, investissements stratégiques… Ces enjeux dépassent la sphère économique : ils ont un impact direct sur la souveraineté industrielle et technologique de l’UE.
Pierre Rousseaux propose également une page dédiée à ce sujet sur son site, qui croise les résultats de son papier avec Isabelle Méjean et ceux réalisés pour la BEI. Elle s’adresse aux publics académique, statistique et politique, et permet d’explorer les vulnérabilités commerciales de l’UE de manière approfondie :
https://www.pierrerousseaux.com/eu-trade-dependencies
Consulter le rapport complet ici.
Électricité, eau, CO2 : pourquoi le Bitcoin est responsable de 95% de l’impact environnemental des cryptomonnaies
Julien Prat pour le média Vert
19/03/2025
Note IPP n°113 : Une étude éclaire l’ampleur du phénomène de la réembauche par le même employeur
L’IPP publie ce mercredi 19 mars une étude consacrée à la question de la réembauche c’est-à-dire le processus par lequel des travailleurs précédemment licenciés ou temporairement au chômage sont rappelés par leur ancien employeur.
Retrouvez la note directement sur le site de l’Institut des Politiques Publiques ici.
Les enseignements principaux de cette étude sont les suivants:
- Il s’agit d’un phénomène massif qui affecte tous les secteurs d’activité : les réembauches représentent environ 44 % de l’ensemble des embauches en France entre 2012 et 2019.
- Les réembauches et le dualisme contractuel sont intimement liés : près de 93 % concernent des contrats à durée déterminée de courte durée, souvent inférieure à un mois.
- La législation encadrant la réembauche ne semble que partiellement appliquée : plus d’un tiers des réembauches pourraient contrevenir au délai de carence obligatoire, et près de la moitié pourraient dépasser la limite légale de renouvellements.
- Les réembauches concernent un groupe relativement restreint de travailleurs, dont un peu plus d’un quart subissent cinq réembauches ou plus par le même employeur chaque année. Elles sont également plus fréquentes chez les femmes et les travailleurs plus âgés;
Les auteurs de l’étude sont Olivier Charlot (professeur à CY Cergy Paris Université, chercheur au THEMA), Franck Malherbet (professeur à l’ENSAE Paris, chercheur affilié à l’IPP) et Eloïse Ménestrier est post-doctorante à la DARES.
Retrouvez également l’article du journal Le Monde : “une étude éclaire l’ampleur du phénomène de la réembauche par le même employeur”, qui se base sur la note IPP.
La réembauche de salariés, levier de précarisation des travailleurs | Alternatives Economiques
ACPR : Patricia Crifo nommée pour ses compétences en protection des clientèles et en techniques quantitative actuarielles
Patricia Crifo nommée pour ses compétences en protections des clientèles et en techniques quantitatives actuarielles parmi deux arrêtés publiés au Journal officiel du 14 mars 2025 qui actent le renouvellement de certaines instances de l’Autorité de contrôle prudentiel et de résolution (ACPR). Plusieurs membres sont ainsi nommés au collège de supervision et à la commission des sanctions.
12/03/2025
Taxe : Pourquoi le chocolat est-il accusé d’avoir « dix catégories fiscales différentes de TVA en France » ?
Pierre Boyer pour 20 minutes
16/03/2025
La stabilité familiale au service de la prospérité, le projet politique et spirituel de JD Vance
Pauline Rossi, pour Le Figaro
12/03/2025
DP20042 The Political Economy of Joint Taxation – Felix Bierbrauer, Pierre Boyer, Andreas Peichl, Daniel Weishaar – 12 Mar 2025
What 10,000 students taught us about combating LGBTphobia in schools
International Women’s Day: what progress for women in Economics?
March 8 is a global day celebrating the achievements of women in every domain. This day gives focus to issues such as gender equality, reproductive rights, and violence and abuse against women. Accordingly to its work, CREST is engaged in supporting women in research at all scale.
Gender inequalities in academic careers in Economics: situation report
As other disciplines, Economics is facing under representation from women, more specifically in more advanced levels in their academic career. According to data collected in 2023 and 2024 by the Women in Economics committee (WinE) from The French Economic Association (AFSE), the proportion of women varies considerably by hierarchical level.
- At junior levels, women represent around 45% of workforce (lecturers, researchers, and post-doctoral fellows).
- As they progress up the career ladder, the proportion of women falls drastically, to just 28% to 31% at the professorial level (university professors, CNRS research directors).
- A regional disparity also exists in Île-de-France (Paris area), the proportion of women is lower than in province, more particularly in more advanced careers.
This phenomenon, commonly called “leaky pipeline”, enlightens the general issue for women to access the most prestigious positions and to progress towards them. Various factors can explain this situation: the weight of stereotypes, less recognition of women’s work, the often greater mental and family burden, as well as systemic barriers such as the lack of female role models and support networks.
Far from being a simple observation, these results led to practical initiatives to encourage women to pursue and grow in an academic career in Economics.
The WinE committee: one initiative to promote Women in Economics.
Facing those inequalities, the French Economic Association (AFSE) launched in 2023 the Women in Economics committee (WinE), nowadays chaired by Prof. Emmanuelle Taugourdeau (CNRS, CREST, Institut Polytechnique de Paris). First, the committee led a thorough study on gender distribution in academic careers in economics in France, inspired by works carried out in the US and in Europe.
In 2024, the committee took a further step forward with the introduction of a mentoring program, aimed at young economists at the start of their careers.
This program is based on a mentor / mentee relationship, where experienced researchers guide doctoral students and young researchers in their professional careers.
The first results are encouraging:
- 90 mentors volunteered to the program, among them 56% of women, demonstrating a strong desire to support withing the profession.
- 57 young researchers applied to the program, including 62% of doctoral students, 29% of postdoctoral fellows, and 9% of economists in early stages of their career.
- 42 pairs were connected: mentees receive their mentor’s contact information and initiate the communication.
Initial feedback from mentors has been very positive: they emphasize the sense of usefulness, and the fact that they can share concrete advice on academic careers and professional challenges.
As for the mentees, several testimonials underline the importance of the feeling of trust and of having a point of reference in an environment sometimes perceived as competitive and solitary.
This program is part of a wider drive to strengthen the presence of women in the economics and facilitate their progress in advanced positions, such as Women in Economics from the European Economics Association, the Committee on the Status of Women on the Economics Profession (CSWEP) from the American Economic Association, or the CEPR Women in Economics Initiative.
Women in Economics at CREST
We are also working with our institutions to promote supportive policies, such as improved maternity leave and reduced teaching loads.
Crest has inherited a poor gender ratio from a historical hiring trend that did not consider gender diversity. It is crucial to actively address gender inequalities, as diversity not only benefits women but also enriches the range of perspectives within institutions. Crest is committed to making these efforts, and progress is already underway.
For instance, in Economics, the recent hiring process for assistant professors resulted in recruiting more women than men (four women versus three men). We are also working with our institutions to promote supportive policies, such as improved maternity leave and reduced teaching loads. Additionally, Crest members strive to foster a collegial and supportive environment to help women find their place in the lab. While this support is often implicit, we strongly believe that such attitudes are essential for enabling women to fully thrive in their roles.
CREST PhD voices from Claire Leroy and Marion Brouard, in their 4th year of PhD, they were on the international job market this year to start their professional academic journey.
In the longer-run, I hope to reach a position in academia which will allow me to participate in these initiatives not as a potential beneficiary but also as someone that can help future generations of women economists after me.
I think that such initiatives are great for women economists. I have heard about several of them during my PhD, but I have never participated in one. On a daily basis, I do not think too much about being a woman in economics right now. One reason why is because as a PhD student at CREST I have generally felt as well regarded as other PhDs regardless of gender and (at least in earlier cohorts when I arrived), there was mostly gender parity in terms of composition of the PhD. However, as a soon-to-be assistant prof, I definitely know (from the many reports and statistics that have been produced and from informal conversations) that there is a lot more struggle for women at the next stage of their academic career.
Therefore, in the future, I think that I will pay closer attention to initiatives like those developed by WinE and participate in it. For example, we know that the tenure track is a key and stressful period where an assistant prof needs to put up a lot of work. Because of the biological clock, this period also often coincides with the time when women will think about having kids if they want ones. While most universities now offer an extension of the tenure clock in this case, research still show that women are penalized with delayed tenure and increased exit of academia after parenthood (Lassen & Ivandic[1]). I believe that committees like WinE can help inform researchers about such important issues, come up with possible solutions and help make them enforced in the profession.
In the longer-run, I hope to reach a position in academia which will allow me to participate in these initiatives not as a potential beneficiary but also as someone that can help future generations of women economists after me.
[1] https://www.aeaweb.org/articles?id=10.1257/pandp.20241118
Beyond awareness, these initiatives help young women find colleagues they can relate to or role models—something that can be difficult in a field where women are still underrepresented.
I haven’t actively participated in Women in Economics initiatives before, partly because CREST has provided me with an inclusive and aware environment. Otherwise, I would have likely joined, and I don’t exclude doing so in the future, as I believe these associations can be incredibly valuable for young women in economics.
Economics remains a male-dominated field, particularly when moving up the academic ladder, and while awareness of gender disparities has grown, inequalities and discrimination still persist. Associations like Women in Economics play an important role in shedding light on these issues, providing a platform for women to speak up, and fostering a sense of community where young women feel heard and supported while not having to worry about how they are perceived. Beyond awareness, these initiatives help young women find colleagues they can relate to or role models—something that can be difficult in a field where women are still underrepresented. For some, having such figures to look up to can make a difference in believing that, as a young woman, you can be successful while staying true to yourself.