Abstract 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 21st Century (r = 0.03, 95% CI 0.03 to 0.04). During the 21st 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.
Rothwell et al. (Mon,) studied this question.