About Me
Hi! I am an Assistant Professor at Columbia Business School in the Decision, Risk, and Operations division and a member of the Data Science Institute. Previously, I received my PhD in Operations Research from Stanford University and was a postdoctoral associate at MIT. I graduated from Pomona College with a degree in mathematics.
My research focuses on running, evaluating, and scaling algorithmic interventions in social systems, like online platforms, education systems, and healthcare systems. In these settings, standard i.i.d. assumptions often break down: capacity is limited, users interact with each other, and interventions create downstream changes in the system. These complications motivate the need for new approaches to data science and machine learning practices in experimentation, recommendation systems, and early warning systems.
I draw on techniques from operations research, statistics, and causal inference both to understand when and why traditional methods fail and to develop better methods. I develop this work through collaborations with industry (Airbnb, Vinted), non-profit organizations (National Institute of Student Success, Keheala), and hospital systems (Columbia University Irving Medical Center/New York Presbyterian).
News
Nov ‘26: I am co-chairing the ACM Conference on Equity and Access in Algorithms, Mechanisms, and Optimization (EAAMO’26), which will be held at held November 5–7, 2026 at LMU Munich. If you have work on the equitable deployment of algorithms, please submit!
Apr ‘26: I am co-chairing the DRO/Deming Workshop on Experimentation for Decision-Making, which will be held at Columbia Business School on May 1, 2026. This workshop will features research developments from industry and academia, with a focus on using experiments to drive better decisions.
Jan ‘26: I gave a talk on our work “Operational Dosage: The Impact of Capacity Constraints on RCT Evaluation” at the Simons 2026 Workshop on Bridging Prediction and Intervention Problems in Social Systems. See abstract and talk recording.
Sep ‘25: Our paper “Wikipedia Contributions in the Wake of ChatGPT” was mentioned in the Wall Street Journal column Will AI Choke Off the Supply of Knowledge? and featured in a Columbia Business School research highlight and video overview.
Contact
Email: hannah.li [at] columbia.edu
For current PhD students interested in working with me, please send me an email. For prospective PhD students, information on admission to the Columbia DRO PhD program can be found here. Please apply to the program and indicate my name in your application and research statement.