Oh look, it's the publication that famously claimed that that the only reason Stephen King was alive today is because he was born in America because the UK health system would have effectively murdered him.
Today, for the first time ever, less than one in 10 people live in this kind of abject state.
Oh, is this the logic where, instead of highlighting specific policies and examining cause/effect, we simply point to good outcomes and say "capitalism did it" while point to bad outcomes and saying "socialism did that"?
What else could explain the shift?
Technology is the biggest change, and government can spur technological growth by investing in it (i.e., the electronic computer, the internet, telecommunication satellites, GPS, etc).
Social progressives is another factor. Encouraging egalitarianism is economically more efficient than discrimination, since you aren't turning away potential talent for stupid reasons.
Infrastructure investments for roads, utilities, postal systems, etc. Along with economic infrastructure in the form of common currencies, banking standards, etc.
Improved distributions for foreign aid, which can be used to help stimulate foreign nations to the next level.
The IBD article doesn't explain how "capitalism" is responsible for growth, nor does it even bother to define the specific policies of capitalism they're referring to. For instance, are they arguing for total laissez-faire? Because that's not what the data show, because the data isn't looking at laissez-faire economies. Are they looking at countries where people are allowed to be motivated by profit? Because if that's the case, then even Bernie Sanders qualifies as a capitalist.
Unfortunately, without any specific policies, the article is completely useless. The fact that the same publication that claimed that Stephen Hawking was only alive thanks to American Privatized Healthcare is now claiming that people only escape poverty due to "capitalism" should be taken with a grain of salt.