A Bayesian Take on Julian Assange
By NATE SILVER*Suppose that you are taking the bullet train from Kyoto, Japan to Tokyo, as I did yesterday. The woman seated across from you has somewhat unusual facial features. You are curious to know whether she is Japanese, Caucasian, or some mix of both.
Suppose furthermore that I asked you to estimate, in percentage terms, the likelihood of each of these three possibilities (ignoring others like that she might be Korean, Latina, etc.) Certainly, there are lots of other clues that we might look for to improve our estimate: How is she dressed? How tall is she? What type of mobile phone is she carrying? What is her posture like? (The more forthright among us, of course, might also seek to start a conversation with her, in which case the answer might become clear more quickly.) That notwithstanding, in the absence of further information, most of us would tend to equivocate: perhaps there is a 25 percent chance that she is Japanese, we might say, a 25 percent chance that she is Caucasian, and a 50 percent chance that she is of mixed ethnicity.
*Nate Silver is an outstanding political analyst and commentator. His blog is part of the NY times. read more here.