But one thing to keep in mind is there is no real penalty for respectable lying in our world of intellectual discourse. Ferguson will almost certainly continue to have a field for his thoughts, regardless of how little effort he puts into stringing them together. The Krugman rebuttal in which Ferguson claims he was only talking about the insurance end (it's detailed in Weisenthal's piece) is not a debatable opinion, but the sort of thing that would raise a red-flag for any fact-checker worth their weight.
When I first started wading my way into the world of ideas, I thought having a big university on your C.V. along a PhD held said something about your trustworthiness. I would have seen that Ferguson was a historian at Harvard and thought, "No way he'd fudge facts. He's a Harvard big-shot who publishes in big magazines." I would have been, of course, dead wrong.
Dishonesty of this sort is insidious. It can't be dismissed with the ease of plagiarism or manufactured evidence. As long you're not egregious, you can actually make a career as respectable public intellectual, and occasionally lie. No one will stop you. Almost no one cares.