CONCEPT
Seventy-to-One
The ratio between per-capita income in the richest and poorest nations at the end of the twentieth century — up from five-to-one before the industrial revolution. The number that, for Segal, broke his confidence about democratization.
Seventy-to-one is the empirical number that anchors the Deaton volume's moral argument. Before the industrial revolution, the ratio between per-capita income in the richest and poorest nations was approximately five-to-one — a gap reflecting modest variation in agricultural productivity and political organization. By the end of the twentieth century, the ratio had widened to roughly seventy-to-one. The great escape had happened: life expectancy doubled, extreme poverty fell, billions of lives improved by every material measure. And the gap widened from five to seventy — not because the poorest got poorer, but because the escapees escaped so far, so fast, that the distance between them and everyone else became a chasm.
In The You On AI Field Guide
The number is the empirical instantiation of the pattern Deaton's career has documented: genuine progress in the aggregate, widening gaps in the distribution. The aggregate improvements in human welfare since the industrial revolution are real and substantial. Life expectancy in wealthy nations approximately doubled.