To people who believe that the world used to be a better place, and especially to those who argue that globalization has done more economic harm than good, there is a simple, powerful riposte: In 1981, some 42 percent of the world's population were extremely poor, according to the World Bank.
They were not just poorer than a large majority of their compatriots, as many rich countries define poverty among their own citizens today, but absolutely destitute. At best, they had barely enough money to eat and pay for necessities like clothes. At worst, they starved.
Since then, the number of people in absolute poverty has fallen by about 1 billion and the number of nonpoor people has gone up by roughly 4 billion. By 2013, the most recent year for which reliable data exist, just 10.7 percent of the world's population was poor. The modern yardstick for destitution is that a person consumes less than $1.90 a day at 2011 purchasing-power parity.
Poverty has almost certainly retreated further since 2013: the World Bank's estimate for 2016 is 9.1 percent. Homi Kharas of the Brookings Institution, a think tank, calculates that someone escapes extreme poverty every 1.2 seconds.
This is impressive and unprecedented.
Economic historians reckon that it took Britain about a century, from the 1820s to the 1920s, to cut extreme poverty from more than 40 percent of its population to below 10 percent. Japan started later, but moved faster. Beginning in the 1870s, the share of its population who were absolutely poor fell from 80 percent to almost nothing in a century. Today two large countries, China and Indonesia, are on course to achieve Japanese levels of poverty reduction more than twice as fast as Japan did.
Unfortunately, this happy chapter in world history is drawing to a close. The share of people living in absolute poverty will almost certainly not decline as quickly in the future — and not because it will hit zero and therefore have nowhere to fall. Even as the global proportion of poor people continues to drift slowly downward, large pockets of poverty will persist, and some of them are likely to swell. The war on want is about to settle into a period of grinding battles in the trenches.
Until recently the world's poorest people could be divided into three big groups: Chinese, Indian and everybody else.