I can think of a couple things that might have contributed. In the second half of the 1960s Chinese government policy switched from encouraging maximally large families to encouraging family planning and control of population growth. In 1970 the 2-child policy was implemented. Since lots of Chinese babies born in that period would have been in extreme poverty it seems likely that played a part. Interestingly 1970 also roughly marks the end of the Great Compression and beginning of the Great Stagnation in the US and many other developed economies. The obvious explanation is that this was the inflection point for a new phase of globalization and labor arbitrage, resulting in stagnant incomes for 1st world workers and higher earnings for 3rd worlders.
Cross-posted from my blog here.
One of the greatest successes of mankind over the last few centuries has been the enormous amount of wealth that has been created. Once upon a time virtually everyone lived in grinding poverty; now, thanks to the forces of science, capitalism and total factor productivity, we produce enough to support a much larger population at a much higher standard of living.
EAs being a highly intellectual lot, our preferred form of ritual celebration is charts. The ordained chart for celebrating this triumph of our people is the Declining Share of People Living in Extreme Poverty Chart.
(Source)
However, as a heretic, I think this chart is a mistake. What is so great about reducing the share? We could achieve that by killing all the poor people, but that would not be a good thing! Life is good, and poverty is not death; it is simply better for it to be rich.
As such, I think this is a much better chart. Here we show the world population. Those in extreme poverty are in purple – not red, for their existence is not bad. Those who the wheels of progress have lifted into wealth unbeknownst to our ancestors, on the other hand, are depicted in blue, rising triumphantly.
Long may their rise continue.