Laurine Martinoty - Una Joint Seminar

UnaJointSem - Program

20/10/2025 - Sara Lazzaroni (University of Bologna) - The Rise of the Knowledge Economy: Republic of Letters and Communication Infrastructures in Early Modern England - Maison des sciences économiques, 106 boulevard de l'Hôpital, 75013 Paris - Salle du 6ème étage.

This paper provides a first formal investigation of the drivers of the diffusion of knowledge in England and Wales in the context of the Republic of Letters, a pan-European, correspondence-based network, formed by a community of intellectuals that shared, distributed, and evaluated knowledge. Using a novel dataset on early modern correspondence in Britain, we document a sharp increase in epistolary communications during the 17th century and identify a plausible catalyst for this change: a postal reform enacted in England in 1635 that made the British postal system openly available to the public. Taking a difference-in-differences approach, we show that locations in England and Wales hosting a postal stage in 1628 (the latest year in the pre-reform period in which we know the whole geographical distribution of the British postal network) exhibited a significant increase in the volume of total correspondence after 1635 relative to places lacking a postal stage in 1628. We also find evidence that the postal reform benefited scholars the most, as after 1635 they started interacting more both among themselves and with practitioners, publishing editors and political figures, to discuss more science-oriented issues. Finally, places with a pre-existing postal stage in 1635 saw a significant increase in innovation activity soon thereafter. These findings provide the first systematic evidence of the rise of knowledge economies in early modern Europe.

15/12/2025 - Max Steinhardt (FU Berlin) - The Impact of Inter-Ethnic Contact in Schools on Managers’ Hiring Decisions - Maison des sciences économiques, 106 boulevard de l'Hôpital, 75013 Paris - Salle du 6ème étage

This paper analyzes whether inter-ethnic contact in childhood affects the hiring behavior of managers. To identify the causal effect of exposure, we exploit quasi-random variation in the share of immigrant students across cohorts within Danish schools. Using administrative employer-employee data, we find that being exposed to more immigrant peers of the same gender in school leads Danish managers to hire more immigrants later in life. Exploring a variety of mechanisms, we find evidence most consistent with a change in managers’ attitudes toward immigrants.

20/04/2026 - Karsten Donnay (U. Zurich) - Lost in Moderation: Making the Case for an Individual-Level Perspective on Harmful Online Content - Maison des sciences économiques, 106 boulevard de l'Hôpital, 75013 Paris - Salle du 6ème étage

Online hate speech and toxic content pose significant threats to democratic discourse, yet policy debates often remain fixated on platform regulation as the primary lever for change. This focus risks obscuring where harm actually originates and who bears its costs. Drawing on experimental and observational research across three countries, this talk makes the case for an individual-level perspective on harmful online content. Relying on scalable approaches that combine human annotation with machine learning classification, we demonstrate that the production of hate speech is highly concentrated: a small minority of users generates the overwhelming majority of harmful content. Platform-wide policies are often poorly equipped to reflect this skewed reality. We show in large-scale social media experiments that counter speech by ordinary users offers a promising complement to top-down moderation, though it may fail to curb the most active hate speech producers. And we illustrate with evidence from a large on-platform experiment that recent shifts from pre- to post-moderation may increase toxicity in subsequent discourse, placing greater weight on such bottom-up, user-driven interventions. Together, these findings underscore why an individual-level perspective is essential to develop effective strategies to curb harmful online content.

08/06/2026 - Lore Vandewalle (KU Leuven) - TBA - Maison des sciences économiques, 106 boulevard de l'Hôpital, 75013 Paris - Salle du 6ème étage

09/06/2026 - Roza Khoban (U. Zurich) - TBA - Maison des sciences économiques, 106 boulevard de l'Hôpital, 75013 Paris - Salle du 6ème étage

XX/11/2026 - Pietro Biroli (U. Bologna) - TBA - Maison des sciences économiques, 106 boulevard de l'Hôpital, 75013 Paris - Salle du 6ème étage

Le projet UnaJointSem, financé sur fonds d’amorçage Paris 1 interne Una Europa, vise à organiser une série de courtes visites de recherche, accueillant des enseignants-chercheurs issus de différentes universités de l’Alliance Una Europa. Chaque visite comprend un séminaire ainsi que des rencontres avec des doctorants et des chercheurs de notre Université. L’objectif est de favoriser les échanges scientifiques, de renforcer la visibilité des travaux de recherche menés dans le cadre de l’Alliance, et de contribuer à l’émergence d’un réseau pluridisciplinaire. Une attention particulière est portée à la parité et à la diversité disciplinaire des participants.

The UnaJointSem project, funded through Una Europa internal seed funding, aims to organize a series of short research visits, welcoming faculty members from various universities within the Una Europa Alliance. Each visit will include a research seminar and meetings with PhD students and permanent faculty members from our University. The goal is to foster academic exchange, enhance the visibility of research conducted within the Alliance, and contribute to the development of a multidisciplinary research network. Particular attention is given to gender balance and disciplinary diversity among the invited scholars.