I agree with Yglesias more often than not and this is a good bias confirmer. Also first time I've read all the way through a Vox article/explainer, think I like the format, apart from being proprietary...

The only deep problem I have with it is it takes national jurisdictions as the sole unit of analysis.

Which brings us to population growth. World population will probably increase by about 2 billion in the next 20 years.