Dr. David Graeber’s newest book ‘Debt’ focuses on the decline of virtual credit with the advent of coinage. This text takes a look at the last 5,000 years of economics, beginning with the agrarian empires, and what it means for today and tomorrow. He’s also a notable anarchist and social/political activist. Here’s a video from Thom Hartmann’s Conversations w/ Great Minds:
The link from his name takes you his wiki page, which has links to many of his articles.
And if you remain intrigued and want more still, Writer’s Voice has a stream-able hour long interview, again about the history of debt.