The Intercept has a long article on Modern Monetary Theory.

In a nutshell: MMT proponents believe that the government can safely spend far more money than it currently does, and increasing the federal deficit is not a bad thing in and of itself — a public deficit is also a private-sector surplus, after all.

While typically we hear rhetoric that our political leaders must first “find” money through new taxes or budget cuts in order to pay for new programs, MMT proponents say that’s a fundamental misunderstanding of how money works. In so-called fiat currency systems (meaning societies in which money isn’t backed by physically valuable commodities like gold or silver) governments literally create the money and tax it later to control for inflation and keep it in demand.

Inflation is still a risk, MMT advocates say, but it’s a much more remote risk than mainstream economists let on, and it’s one that can be addressed down the line if it arises, without so much pre-emptive austerity.

They also talk about the idea of a federal jobs guarantee.

I just had a few college economics courses, but the idea seems risky. By expanding the money supply so drastically, I thought you risked hyper-inflation and a devaluing of your currency relative to others. Of course the U.S. can push it further than other countries, but there still must be a breaking point. But the idea of some kind of counter-cyclical automatic investment in infrastructure, education, training, and research is appealing to me. This could kick in if unemployment hits a certain level, growth falls below a certain level, or some combination of the two. Then during stronger economic times, the government steps back and lets the private sector take the lead. I think it would have to be some kind of formula or else the politicians will ruin it.