Last month marked a global tipping point. For the first time in the 10,000 years of human civilization, more than half the world's population — some 3.8 billion people — are middle class, according to a report by the Brookings Institution.
Why it matters: Since the agricultural age led humans to organize into society, we have struggled. Through the early 19th century, civilization as a whole was essentially hand to mouth. Beginning with the Industrial Age, though, living standards began to improve. As of now, the number of poor people is down to 630 million people — 8% of the world population, say Brookings' Homi Kharas and Kristofer Hamel.