Public deficits = net private savings

From the other thread, razerfish mentioned that the underlying theory might be something called MMT or Modern Monetary Theory.

Basically, MMT is another name for Chartalism, which is Post-Keynesian theory (yes, that is an actual school).

In general, I think it’s prudent to familiarize yourself with other schools of thought, even other non-mainstream ones, in the event you encounter some of their adherents.

Here are some useful links after I did a google search:

Wikipedia: Chartalism

Wikipedia: Monetary Circuit Theory

A Primer on Modern Monetary Theory (MMT)