Modern Monetary Theory: What's Modern About It?

In a newspaper that relies on the same old crew of reliably wrong experts for the vast majority of its economic reporting, it's good to see this piece by Dylan Matthews on Modern Monetary Theory (MMT). I've had many people ask me my assessment of MMT.

I consider many of the leading proponents of MMT to be friends and generally find myself on the same side of political debates. However, I have to confess to being a bit unclear as to what exactly separates MMT from the good old Keynesian...