Keynote Speakers

Clément de Chaisemartin (Sciences Po) — Lecture on January 22nd

Title: "Credible Answers to Hard Questions: Differences-in-Differences for Natural Experiments" Link

Abstract: The purpose of this book is to introduce applied researchers to modern Differences-in-Differences (DID) estimators, tailored to potentially complicated natural experiments, that they can use to obtain credible answers to hard causal inference questions, for which randomized experiments are unfeasible.

Clément de Chaisemartin is a Professor of Economics at Sciences Po and a J-PAL Affiliate. He is the Principal Investigator of the ERC-funded research project REALLYCREDIBLE. His research focuses on developing credible methods for impact evaluation, with a particular emphasis on modern differences-in-differences estimators. He is co-author of the forthcoming textbook Credible Answers to Hard Questions: Differences-in-Differences for Natural Experiments (with Xavier D’Haultfoeuille). Clément de Chaisemartin also develops widely used open-source tools in Stata and R, including did_multiplegt_dyn and twowayfeweights. His work has been published in leading economic journals such as American Economic Review, Econometrica, Review of Economic Studies, Journal of Econometrics, and AEJ: Applied Economics. He earned his PhD in Economics from the École des Hautes Études en Sciences Sociales (EHESS) and the Paris School of Economics (PSE). Prior to joining Sciences Po, Clément de Chaisemartin held permanent faculty positions at the University of Warwick and the University of California, Santa Barbara.

Learn more about Clément and his work on his homepage.

Alessandra Casella (Columbia University) — Lecture on January 23rd

Title:  "Women, Men, and Polya Urns. Underrepresentation at Equal Talent in the Absence of Discrimination" (with Laura Caron and Victoria Mooers). 

Abstract: In a world where the majority and the minority group have equal distributions of talent, where candidates are objectively and accurately evaluated, and no discrimination occurs, the underrepresentation of the minority group in prestigious positions can remain highly sticky. If the sample of candidates from the minority group is numerically smaller, at equal distribution of talent, the most qualified candidate is more likely to belong to the majority sample, mirroring its larger numerical size. If future samples of candidates respond to the realized selection in the expected direction—increasing more if the selection came from the sample—the higher probability of success in the majority sample will persist. We capture this process through the statistical model of Polya urns. The richness of existing results and the streamlined model allow us to study and compare different policy interventions. Two robust results are that temporary affirmative action interventions have long-term equalizing effects, and that any decline in the quality of selected candidates is self-correcting, even while the intervention lasts. A simple app (https://caron.shinyapps.io/Women-Men-Polya-Urns/) allows readers to run their own experiments.

Alessandra Casella is a Professor of Economics and Political Science at Columbia University, where she co-directs the Institute for Social and Economic Research and Policy (ISERP). She is a fellow of the Econometric Society and of the Society for the Advancement of Economic Theory and a member of NBER and CEPR. At Columbia, she founded the Columbia Experimental Laboratory for the Social Sciences (CELSS), which she directed from 2012 to 2022.  Her current research focuses on voting behavior and theoretical experimental political economy. She is the author of Storable Votes: Protecting the Minority Voice (Oxford University Press, 2012). Her work has been published in top journals including Econometrica, American Economic Review, Journal of Political Economy, Review of Economic Studies, and Games and Economic Behavior. She has been the recipient of numerous fellowships: she has been a Guggenheim fellow, a member of the Institute of Advanced Studies in Princeton, a Russell Sage fellow, and a Straus fellow at the NYU Law School. Alessandra Casella earned her PhD in Economics from MIT, and she previously served as Directeur d’Études at the École des Hautes Études en Sciences Sociales (EHESS) in Paris and Marseille.

Learn more about Alessandra and her work on her homepage.