Trader Selectivity and Measured Catch-Up Growth of American Slaves

Critics who doubt the sources and meaning of some four inches of catch-up growth claim that market-based distortions created by slave traders biased measured heights of children and adolescents. Here we analyze this possible bias using a new database of all slave manifests available at the National Archives. Employing procedures to match names of shippers with known or suspected professional traders, we find that biases in height by age due to trader selectivity were negligible relative to the four inches of catch-up growth.