The Deep Roots of Inequality

This paper shows and explains lower wealth inequality in East Asia than Western Europe over the very long-run, 1300-2000. A rich new dataset of village censuses in Japan, 1640-1870, and secondary evidence suggest Gini coefficients of wealth inequality in the East were 0.4-0.5 relative to 0.7-0.9 in the West preceding industrialization. Such regional patterns also precede the black death so any explanation must predate this. I propose the demographic institution of adoption as one such explanation. Adoption prevented the failure of male lines through which wealth was inherited. Adoption was practiced across Eurasia until the 5th century when the church began preaching against it. This increased household extinctions in Europe causing wealth concentration among surviving male lines. In contrast, the Japanese data suggest adoption prevented household extinctions and kept wealth in the family. Simulations show that this mechanism can explain much of the gap in regional wealth inequality.