As far as I can tell, "globalism" is the biggest cause of inequality. It's not about QE or easy monetary policy. It's about the fact that I don't have to pay a guy next door high wages to have something done. I can pay someone in a developing nation 10x less to do the same thing. Doing this at scale is what got us in to this mess.
Some argue that globalism was inevitable, others that there is some shadowy group pushing an agenda. But whatever you believe, one outcome of globalization (and there are positives as well) but one negative outcome is income inequality.
What bugs me about this article is that these people think they can solve inequality with MORE globalism ("global" taxes, regulating international companies etc). I don't think doubling down on it is going to fix anything.
You know how you fix capitalism? You break apart the huge companies. You incentivize smaller companies (with progressive corporate income taxes and other things). Competition will yield lower prices and more innovation.