Stone Inequality & Social Policy Seminar: 2026 Stone Scholar Symposium

The second Stone Scholar Symposium will take place on Monday, April 27, 2026. This event features two Stone PhD Scholars who will present their research in the Stone Inequality & Social Policy Seminar. Lunch will be provided. Bell Hall (B-500) is located on the fifth floor of the Belfer Building at the Harvard Kennedy School. 

Featuring:

Johann D. Gaebler

PhD Candidate in Statistics and Stone PhD Scholar in Inequality and Wealth Concentration

A Simple, Statistically Robust Test of Discrimination

Abstract: Imagine auditing a bank for discrimination. If one group of borrowers repays their loans more than other groups, that suggests the bank held them to a more stringent standard, only lending to the most creditworthy applicants from that group. Such "outcome tests" are one of the most common empirical approaches for detecting double standards in lending, hiring, criminal justice, and other domains. Despite their simplicity, outcome tests suffer from well-known statistical issues and often miss discrimination or even mistake discrimination for favorable treatment. "Benchmark tests"—where, for example, researchers directly compare lending rates across different groups—are the most common alternative, but suffer from their own deep limitations. Here we introduce a robust outcome test, which considers both the rate at which decisions are made (benchmark tests) and how often those decisions succeed (outcome tests). Despite their individual fallibility, carefully combining benchmark and outcome tests retains the simplicity of the original approaches while yielding surprisingly strong statistical guarantees under a common non-parametric assumption that we show—both empirically and theoretically—likely holds approximately in real-world data. We illustrate our robust outcome test with 2.8 million police stops from across California, finding evidence of widespread racial discrimination, a pattern that the standard outcome test would miss.

Johann D. Gaebler is a Ph.D. candidate in Statistics at Harvard University and incoming assistant professor in the Department of Technology, Operations, and Statistics at NYU Stern. His research uses computational methods, including generative AI, to improve organizational decision making and public policy in areas like hiring, education, and criminal justice. His research—spanning computational social science, statistics, and AI—has informed litigation in federal court and appeared in venues including PNAS, JMLR, and ICML, where it was awarded an outstanding paper award. Previously, Johann obtained his Bachelor’s in Mathematics at Harvard, and worked as a data scientist at the Stanford Computational Policy Lab.

Avi Moorthy

PhD Candidate in Public Policy and Stone PhD Scholar in Inequality and Wealth Concentration

The Defender on the Move: Black Newspapers and the Great Migration

Abstract: After 50 years of limited migration following emancipation, 1.5 million Black southerners made the journey north during the First Great Migration from 1915 to 1940. I examine whether information on northern life and jobs sparked Black migration using quasi-random variation in exposure to the Chicago Defender, the most prominent northern Black newspaper. Classifying the coverage of thousands of southern newspapers, I show that information about the North was limited prior to the Chicago Defender's entry in the mid-1910s. To reach southern readers, the Chicago Defender partnered with Black railway porters working for the Illinois Central railroad. In cities along the railroad, I find that individuals who lived near a porter were 33% more likely to migrate north than similar individuals who did not. These individuals pulled relatives to migrate, consistent with information diffusion across social networks, and moved to cities that received more coverage in articles, ads, and job postings. Counties with access to the Chicago Defender were 1.5 times more likely to form an NAACP branch and experienced 1.4 times fewer lynchings.

Avi Moorthy is a Ph.D. candidate in Public Policy at Harvard University and a Stone Ph.D. Scholar, focusing on the intersection of labour economics, economic history, and social policy. His research examines the effects of access to information and education reaching lower-resourced communities. At Harvard, Avi is an affiliate of the Centre for International Development, Evidence for Policy Design, and the Harvard Environmental Economics Program. Before Harvard, Avi worked at the Federal Reserve Bank of Chicago and graduated from Carleton College. Avi is originally from Toronto, Canada and is currently watching the Wire.