Missing Data and Causal Inference
We propose a new estimator to deal with confounders missing at random, in observational causal inference settings.
We decompose bias in synthetic control methods with missing control-unit data and develop a sensitivity tool for bias calibration.
Algorithms and LLMs
We conduct a large-scale experiment to measure ideological biases in major commercial large language models.
Using an experimental design that mimics the YouTube interface, we demonstrate that presenting people with more partisan video recommendations has no detectable polarizing effects on users’ attitudes in the short term.
Text as Data
We propose a new method for measuring public opinion in sensitive survey contexts and validate it using data from mainland China and Hong Kong.
This is the second course in the PhD method sequence at Government department.
This is the second course in the data science track by the Government department at Harvard.
This is the fourth course in the PhD method sequence at Government department.

Assistant professor of Government
at Harvard (political methodology).
naijialiu[at]fas.harvard.edu
1737 Cambridge St,
Cambridge, MA