Plenty has already been said about Niall Ferguson's gaffe in which he attributed Keynes's belief in his economic ideas to his homosexuality and lack of offspring. Ferguson issued an unqualified apology, except that, you know, he still believes what he said.
Now, I personally don't think Ferguson is necessarily anti-gay. He claims not to have any objection to homosexuality, and I will take him at his word. But, I think there is a deeper issue than that--his comments, attributing a person's professional opinions entirely to his personal life, reveal that Niall Ferguson isn't just bad at economics; he is also bad at History.
I say this as someone who, unlike Ferguson, has degrees in both history and economics. Ferguson bills himself as an "economic historian," but what you need to know is that there are two types of economic historians: there are economists who study historical topics, and then there are historians who study economic topics. Ferguson is the latter. There is nothing wrong with that--economics has been a powerful influence on history, and it is entirely appropriate to study that--but it means that Ferguson has literally no training in social science, policy analysis, or economics. He is an historian. That's an important distinction because it really is inappropriate for historians to give policy advice. Sure, Ferguson is entitled to give his opinion, same as anyone else, but we should recognize that Ferguson does not do so from a position of authority--he is not a social scientist, and has no background in policy analysis techniques. If you still don't believe me that Ferguson should not be giving policy advice, let me explain with an analogy: Roy Porter held a doctorate in history from Cambridge, and wrote The Greatest Benefit to Mankind: A Medical History of Humanity. He was one of the world's leading medical historians; would you trust him to be your physician when you get sick? Like I said, Roy Porter would be entitled to say what he thinks about your illness, but not from a position of authority--you need to get yourself someone who, you know, went to med school.
But even when we examine Niall Ferguson's historical analysis, we also find it lacking. Ferguson's view that Keynes's sexuality directed his economic theories has permeated much of his work throughout his career. Brad Delong finds Ferguson way back in 1995 writing that Keynes's desire for more leniency towards the Germans in the Treaty of Versailles, as well as his inflation-dove views, were attributable to his homosexual affair with a German staffer at the treaty negotiations. This is all kinds of wrong. For one, the British in general, not just Keynes, pushed for more leniency for the Germans--this is well established in the historical literature, and wasn't because all British politicians had gay crushes on German boys. Besides, are we really to believe that there were no heterosexual affairs at Versailles? Ferguson really does single Keynes out for his sexual orientation. Second, Ferguson actually admits that Keynes's "affair" was not sexual at all. So, (if it was anything) it was really more of a bromance--what does that have to do with Keynes's sexual orientation? Are we to believe that had Keynes been straight, he would never have befriended any Germans?
But my real point is this: Ferguson's suggestion that an economist's professional theories are based on his personal life only makes sense if you don't think about it. For illustration, consider Nate Silver. He is gay. He predicted Obama would win in 2012. Obama supports gay marriage. Using Ferguson's reasoning, Nate Silver's professional forecast was a result of his desire to see a pro-gay president win re-election--and in fact, there were lots of right wing commentators who dismissed Silver's forecasts for precisely this reason. In reality, however, Nate Silver's forecast was based not on his personal sexual orientation, but on the overwhelming weight of the evidence. Nate Silver might be gay, but his statistical forecasting models most certainly do not have a sexual orientation. Any suggestion that Silver's forecasts were personal rather than scientific is simply wrong, if not downright offensive.
With Keynes, it is much the same story. The only way you can claim that Keynes's views on inflation or counter-cyclical fiscal policy were a consequence of his personal life--gay or straight, children or childless--is if you completely ignore all of the actual science he conducted, arguments he made, evidence he presented.
Niall Ferguson's problem isn't that he's homophobic. It isn't even that he lacks training in the social sciences. His real problem is that he is a bad historian. My hope is that Ferguson's gay problem will be his "excel error" moment, and that people will now start to reconsider his qualifications.