I've been thinking a bit about information asymmetries. I opposed the Iraq war from the start -- it seemed to me that for the invasion to make sense, almost everything had to break our way, so the invasion was akin to making a bet with a 1:1 payoff that you would win only if you rolled snake eyes. The one thing that gave me pause was the confidence George Bush and his advisers had about Saddam Hussein having weapons of mass destruction. If Saddam had WMD, and there was an imminent danger of his using them, then it seemed to me that the cost/benefit ratio of the war was much closer. And Bush had access to information that I could not see. So a huge issue for me (and I'd bet for many others) was the magnitude and significance of the information asymmetry between me and Bush. I ended up concluding that the public case for Saddam's WMD seemed sufficiently spotty that the information asymmetry was not huge, but of course that was just an educated guess. Only in retrospect does it seem clear that Bush may have thought that he had much more information than the rest of us did, but that information turned out to be unreliable (note to future Presidents: be wary about relying on sources codenamed "Curveball").
When Mike Nifong stated that "there is no doubt a sexual assault took place" (and made more specific claims, like that the alleged victim "was struggling just to be able to breathe" during the alleged attack), again the information asymmetry loomed large. My assumption (like that of most people I know) was that he must have had mounds of evidence to support his confidence. Like Bush with WMD, Nifong had access to information that I could not see, and that access seemed important. It now seems that the only evidence he had for his statements was the alleged victim's multiple (and contradictory) statements, and Nifong's confidence (and the whole case) has become some combination of tragedy and farce.
The question that interests me is whether we can articulate any useful metrics for when we should defer to self-serving statements by those with access to more information, and when we should not. In the two instances above, the doubters were vindicated. There are other examples in this vein. LBJ had access to greater information about the Gulf of Tonkin incident than did the doubters, but the latter were right, as the Pentagon and LBJ misrepresented what happened. Indeed, the Pentagon Papers revealed repeated such instances in the Vietnam War. Meanwhile, General DeWitt emphasized his access to information as justifying the government's Japanese internment in World War II, but we now know that DeWitt simply fabricated and lied (see Eric Muller and Peter Irons on this).
But there are counter-examples. Many people believed that Julius Rosenberg was innocent, but it is now clear the government really did have the goods on him, and that he was guilty. Same for Alger Hiss. Indeed, the airstrikes that President Clinton ordered at the height of the Lewinsky imbroglio -- which were widely criticized as trumped up attempts at diverting attention, with little deference to the information asymmetry favoring the President -- look quite different after September 11, 2001.
So I return to my question: are there any useful guideposts for how much (if at all) we should defer to self-serving claims that rely on superior information? Or are we left to judge each instance on an ad hoc basis?