If you've ever doubted that 2015 is the best time to be alive in human history to date, take a look at this chart:
In the 19th century, extreme poverty — defined here as living on less than $1.25 a day* — was the norm. In 1820, 94.4 percent of humans were below that line. Only a tiny fraction of the world enjoyed standards of living that were remotely bearable. Progress was initially slow. By 1910, the share had only gotten down to 82.4 percent — a 12-point drop over 90 years. But things picked up after World War II, and 89 years after 1910, only 28.9 percent of people were in extreme poverty. To repeat: From 1820 to 1910, there was a 12-point drop. From 1910 to 1999, there was more than a 53-point drop. Progress in the 20th century was just dramatically faster, especially once China and India began growing quickly.
In 2011, the most recent year represented in the chart, the extreme poverty rate had been cut to half its 1999 level: 14.4 percent. There's still much work to be done: 14.4 percent of the world amounts to 1 billion people who still need to be lifted out of extreme poverty. And making sure everyone's making at least $1.25 a day isn't the end of the fight either. The world's median income is still only $3 to $4 a day. By comparison, the poverty line in the US for a family of four is $16.61 per person per day. Once under-$1.25-a-day poverty is eradicated, the world needs to set about eradicating under-$15-a-day poverty, which will be a substantially harder task.
* Adjusted for different purchasing power in different countries. So yes, it is taking into account the fact that things are often cheaper in poorer countries.