Dylan Matthews in Vox:
“The 140 years from 1870 to 2010 of the long twentieth century were, I strongly believe, the most consequential years of all humanity’s centuries.” So argues Slouching Towards Utopia: An Economic History of the Twentieth Century, the new magnum opus from UC Berkeley professor Brad DeLong. It’s a bold claim. Homo sapiens has been around for at least 300,000 years; the “long twentieth century” represents 0.05 percent of that history.
But to DeLong, who beyond his academic work is known for his widely read blog on economics, something incredible happened in that sliver of time that eluded our species for the other 99.95 percent of our history. Whereas before 1870, technological progress proceeded slowly, if at all, after 1870 it accelerated dramatically. And especially for residents of rich countries, this technological progress brought a world of unprecedented plenty. DeLong reports that in 1870, an average unskilled male worker living in London could afford 5,000 calories for himself and his family on his daily wages. That was more than the 3,000 calories he could’ve afforded in 1600, a 66 percent increase — progress, to be sure. But by 2010, the same worker could afford 2.4 million calories a day, a nearly five hundred fold increase.