ProPublica reports racial bias in COMPAS risk scores (2016). Korvaax

ProPublica reports racial bias in COMPAS risk scores

Julia Angwin, Jeff Larson, Surya Mattu and Lauren Kirchner analyzed Northpointe’s COMPAS recidivism software, used by courts across the United States, and found Black defendants nearly twice as likely as white defendants to be wrongly flagged as high risk.

Why it mattered Northpointe disputed the statistical method. The exchange set the terms for a decade of research on fairness in algorithmic decisions about people.

Corrections

2026-09-07 - The “Machine Bias” article was labeled a primary source. It is a news investigation, not an official document from Northpointe (the maker of COMPAS), so it is relabeled secondary; both cited sources are now secondary, consistent with the rule that a news article is never primary.
2026-09-13 - Added an independent reanalysis published by The Washington Post. The two ProPublica articles were from one publisher and did not meet the requirement for two independent secondary sources.