Founded in 1920, the NBER is a private, non-profit, non-partisan organization dedicated to conducting economic research and to disseminating research findings among academics, public policy makers, an...

I'm currently returning to Toronto from a summit on the future of mathematics, at OpenAI. Sebastian Bubeck asked me to talk a bit about the future we'd all…

The actual prevalence, researchers said, may be much higher.

(Forthcoming Article) - This paper analyzes difference-in-differences designs with a continuous treatment. We show that treatment-on-the-treated-type parameters are identified under a parallel trends assumption analogous to the binary treatment case. However, comparing these parameters across treatments is challenging because parallel trends does not rule out selection bias. We discuss alternative, typically stronger, assumptions that eliminate selection bias. We further show that popular two-way fixed effects estimands admit multiple interpretations, depending on the underlying causal building block, all having important limitations as meaningful summaries of treatment effects. Finally, we introduce alternative estimation procedures that avoid these drawbacks and demonstrate them in an empirical application.

My keynote at ICML 2026

Explaining Rural Conservatism: Political Consequences of Technological Change in the Great Plains - Volume 119 Issue 1

Recruited to Magnum Photos by Henri Cartier-Bresson in 1977, the veteran photographer, who has died aged 83, made defining images of grand and intimate Indian life for five decades

Table of contents for Comparative Political Studies, 59, 6

Local Power and the Social Order