Machine learning algorithms are widely used for decision-making in societally high-stakes settings from child welfare and criminal justice to healthcare and consumer lending. Recent history has illuminated numerous examples where these algorithms proved unreliable or inequitable. In this talk I show how causal inference enables us to more reliably evaluate such algorithms’ performance and equity implications.
In the first part of the talk, I demonstrate that standard evaluation procedures fail to address missing data and as a result, often produce invalid assessments of algorithmic performance. I propose a new evaluation framework that addresses missing data by using counterfactual techniques to estimate unknown outcomes. Using this framework, I propose counterfactual analogues of common predictive performance and algorithmic fairness metrics that are tailored to decision-making settings. I provide double machine learning-style estimators for these metrics that achieve fast rates & asymptotic normality under flexible nonparametric conditions. I present empirical results in the child welfare setting using data from Allegheny County’s Department of Human Services.
In the second half of the talk, I propose novel causal inference methods to audit for bias in key decision points in contexts where machine learning algorithms are used. A common challenge is that data about decisions are often observed under outcome-dependent sampling. I develop a counterfactual audit for biased decision-making in settings with outcome-dependent data. Using data from the Stanford Open Policing Project, I demonstrate how this method can identify racial bias in the most common entry point to the criminal justice system: police traffic stops. To conclude, I situate my work in the broader question of governance in responsible machine learning.
Bio: Amanda Coston is a PhD student in Machine Learning and Public Policy at Carnegie Mellon University. Her research investigates how to make algorithmic decision-making more reliable and more equitable using causal inference and machine learning. Prior to her PhD, she worked at Microsoft, the consultancy Teneo, and the Nairobi-based startup HiviSasa. She earned a B.S.E from Princeton in computer science with a certificate in public policy. Amanda is a Meta Research PhD Fellow, K & L Gates Presidential Fellow in Ethics and Computational Technologies, and NSF GRFP Fellow, and has received several Rising Star honors.
This seminar is cosponsored by the Center for Information Technology Policy and the department of Computer Science.
To request accommodations for a disability please contact Emily Lawrence, emilyl@cs.princeton.edu, at least one week prior to the event.