Millions of Decisions: The Level and Trajectory of Racial Discrimination Since 1910

This paper introduces and analyzes a massive new meta-database of over 400 effect-size estimates of racial discrimination in the United States based on 242 million decisions, covering 1910 to 2025. The measures quantify the effect of Black compared to White race across a variety of domains. To harmonize data from many sources, we created and validated novel algorithms to recover missing standard errors. Our pre-registered analysis finds that anti-Black discrimination during the Jim Crow era (1910 to 1964) was hyperendemic, extremely pervasive overall and across domains, affecting most decisions (r=0.87, 95% CI 0.82-0.91). Discrimination fell dramatically during the Civil Rights era (1965-1999) (r=0.18) and further still in the 21 ^st Century (r = 0.03, 95% CI 0.03 to 0.04). During the 21 ^st Century, we estimate that anti-Black discrimination explains one out of every 1,111 decisions, and the effects of race on decisions are small, despite reaching statistical significance in most estimates.