This is an idea I have seen floated about on a few right-leaning economic blogs already; left-of-center bloggers responded with why it was a really stupid idea, which was that once you make something profitable, d'oh, people do more of it.
The commenters on the blogs, though, were who interested me. You can imagine the comments.
Anyway, I ran with that idea, especially since I had been reading half a dozen other books at the same time -- Billy Bragg, and Octavia Butler's work, and Adam Hochschild's Bury the Chains, and I forget the others. I didn't read Douglas Blackmon's Slavery By Another Name until later, but that book got folded into my research on the revision level.
However: look here. Apparently what I thought was fiction, ain't. And I am entirely off on the year. Go figure.