A remarkable feature of the recent global financial crisis is that so many of the lavishly rewarded analysts on Wall Street and in the City of London failed to see it coming. Seemingly ignorant of history’s lessons, they viewed a catastrophic reversal of fortune as inconceivable. The history books record the green stains on the marble floor of the Basilica Aemilia in Rome, all that remains of the coins abandoned by money changers who continued to trade oblivious of the Goths breaching the city walls; the rise and fall of the market in tulips in 17th century Holland; and the South Sea bubble. Even recent memory of last decade’s dot.com bubble seems to have been repressed.

The progress of nations, however, is measured in much more than wealth. Indeed, there is growing recognition, advanced by the ideas of economics Nobel laureate Amartya Sen,1 that measures such as life expectancy are crucial indicators. On this count we may seem to have less to worry about. Overall, humankind has done well over recent centuries. Although historical …