Ian B gives us this interesting number in the comments:
It might be due to a lack of world wars (it took until 1960 for world economic output to return to 1914 levels),
It’s a fun number but sadly it’s wrong.
The Maddison Project numbers are chained (ie, inflation adjusted) and per capita, and in 1913 world GDP per capita was $1,543.
In 1960 it was $2,764. In 1940 it was $2,181. In 1950 it was $2,104, and in 1951 it had reached above that 1940 number at $2,191.
Sadly, we don’t have the world number calculated for every year….in fact we’ve only got it for 1914, 1940 and then 1950 onwards.
We do have fuller figures for smaller areas: Latin and North America both grew during WWI. Western Europe was back up to pre WWI numbers by 1924. Even the Soviet Union recovered from the Civil War shite by 1930.
I just cannot see anything at all that could possibly support the initial claim.
And further, do note that these are GDP per capita numbers.
If we add in the number of humans then in 1914 it was some 1.75 billion, in 1927 some 2 billion and in 1960 3 billion. So gross economic output was obviously higher if there were more people with a higher GDP per capita.
And note an implication of IanB’s claim. If gross output in 1960 was the same as that in 1914, but we have 50% more people, then each of those people must be, on average, 33% poorer. Which isn’t, I think, a claim that we’d really want to make.
It’s a fun number alright, just don’t think it’s accurate.