Jason Kissner uses Bayes’s theorem to analyze the impact the 1991-2007 literary agency’s statement that Obama was born in Kenya should have on rational probability assignments. Even if one starts by assigning a very high probability to the assertion that Obama was born in the United States, reasonable assignments to the likelihood that an agent would claim him to have been born in Kenya if he was born in Kenya and that an agent would claim him to have been born to Kenya if he were not born in Kenya lead to the conclusion that he is more likely to have been born in Kenya than not. To those who are not familiar with Bayes’s theorem, this can all seem like elaborate wordplay. To those who are, however, it quantifies the rational implications of new information in sometimes startling ways. This is such a case.
The key implication, I think, is not the probability assignment itself but the indication of where to look for new information:
Be those things as they may, if you believe that the Obama campaign is not telling the truth on this issue, you might reason as follows. Perhaps Mr. Obama, as many have suggested, was simply trying to appear exotic? Or, perhaps Mr. Obama was simply trying to enhance the marketability of his book? Once again, that’s not what the campaign says, but it’s possible, so let’s look at matters under the assumption of intentional misrepresentation just in case there has been a misunderstanding.
The “intentional misrepresentation” view might be a reasonable view (particularly if one has good reasons to explain the inconsistency with the campaign’s current statement), but how many people have considered that if Ms. Gonderich is not telling the truth (meaning that Mr. Obama did contribute to misrepresentation of his place of birth and that Mr. Obama’s campaign is currently not telling the truth), one of the following two things must be true:
- Mr. Obama had special reasons to restrict his misrepresentations to her agency OR
- There is a reasonable likelihood that there are other documents containing misrepresentations of Mr. Obama’s place of birth.
It follows under the supposition of intentional misrepresentation that if one wishes to make a rational case for the belief that the promotional booklet’s declaration that Mr. Obama was born in Kenya has nothing much to do with the likelihood that he really was, one should either provide good reasons for thinking that Mr. Obama had good reasons to misrepresent his place of birth, but only to his literary agency, or make a reasonable attempt to locate another document — itself obviously not dispositive of the issue and also independent of literary agency processes — paradoxically indicating that Mr. Obama was born in Kenya.
Bayes’s theorem not only shows how powerful an impact this revelation should have on probability assignments but raises new questions. He surely had to list a birthplace on many documents between 1991 and 2007. After all, he got married in 1992, joined a law firm and began teaching part-time at the University of Chicago in 1993, started working on the Chicago Annenberg Challenge in 1995, was elected to the Illinois State Senate in 1996, ran for the House of Representatives in 2000, and ran for the Senate in 2004. There must be quite a few documents filed during that period that list a birthplace. What do those documents say?