PISA‑D’s stark Africa–U.S. gap

Because PISA‑D is calibrated to the main PISA scale, Zambia’s 275 average versus U.S. Black students’ 459 implies about a 1.8 standard‑deviation difference in reading. That magnitude suggests schooling quality and broader environment drive much of the disparity, not ancestry alone. It reframes how we compare U.S. subgroup performance to developing countries. — It injects hard numbers into contentious education and heredity debates while highlighting the scale of global human‑capital deficits.