A Bayesian Take on Julian Assange

230px-Julian_Assange_(Norway,_March_2010) Nate Silver in 538 (h/t: mr goodbar):

Psychologists and behavioral economists have conducted a lot of experiments along these lines, testing our ability to think through problems that involve what statisticians call Bayesian inference: those that require to us to infer the likelihood of various possibilities based on a combination of prior, underlying conditions (we are in Japan: most people we encounter here will be of Japanese ancestry) and new information (but based on this woman’s appearance, it is hard to tell whether she is Caucasian or Japanese!) They’ve found that, in general, we do pretty badly with them: we tend to get lost in the most immediate details and we forget the underlying context.

I was reminded about this recently when reading WikiLeaks founder Julian Assange, who is wanted for questioning by Swedish authorities on charges that that he has committed sexual assault. People have spent a lot of time debating the details of the charges, which invoke a number of difficult questions about what constitutes consent during a sexual encounter. Commenters differ in their interpretations both about the facts intrinsic to the case and in their readings of Swedish law.

I certainly do not intend to resolve those debates, although they are by no means uninteresting or unimportant. What I would suggest, however, is that it would be a mistake, from the standpoint of Bayesian reasoning, to think we can separate out the merits of the charges from their political motivations.

There is virtually no chance that the case against Mr. Assange would have proceeded in quite the same manner if he were instead an itinerant painter named Jens Andersen, or a traveling salesman named John Andrews — instead of an internationally renowned provocateur. Indeed, the charges might not have been brought against Mr. Assange in the first place. Sweden has among the highest rates of reported rape cases in the European Union. But unfortunately, few cases are brought to trial (only between 10 and 20 percent, according to various reports), and fewer still result in convictions.

That alone might not tell us much. There are other ways, however, in which the behavior of the authorities has been quite unusual.

The initial warrant in the case against Mr. Assange had been issued in August. But it was revoked the next day, due to what the lead prosecutor cited as a lack of evidence. It was only last month – just as WikiLeaks was preparing to release a set of confidential diplomatic cables – that Sweden again issued a warrant to detain him.

Photo from wikipedia.