Fun with Intrade Predictions Market and Conditional Probability

Obama campaign’s generating scandals, indicating that their candidate is dissembling for votes and saying that Hillary’s a monster. Shocking, I know. But seemingly it doesn’t matter, because Hillary shares are at .28%, right?

Well, not quite. Hillary’s weakness is that she needs to keep winning to be competitive. If she loses Pennsylvania, say, it’s over.

But that also means that, if one assumes that Hillary will win Pennsylvania, she has a real shot at being the Democratic nominee. Currently, Intrade‘s Hillaryshares for winning Pennsylvania are 73.5.

Let’s call Hillary winning Pennsylvania “A,” and Hillary winning the nomination “B” Therefore

P(A), the probability of Hillary winning the nomination, is .280
P(B), the probability of Hillary winning Pennsylvania, is .735

Now, I’m assuming that it’s impossible for Hillary to win the nomination if she loses Pennsylvania. Losing Pennsylvania would not only let Obama finally win a “big state,” but one tailor-made for Hillary to walk all over him in. So P(A,B), the probability of Hillary winning both the nomination and Pennsylvania, is the same as her winning the nomination; therefore, P(A,B) = P(A) = .280.

Now, in conditional probability, the probability of Hillary winning the nomination assuming that she wins Pennsylvania would be written P(A|B), and can be figured as such:

P(A|B) = P(A,B) / P(B)

because P(A,B) = P(A) = .280, and P(B) = .735, then P(A|B) = .280 / .735 = .381.

According to inTrade and conditional probability, if Hillary wins Pennsylvania,then she has nearly a 40% chance of being the Democratic nominee.

Considering that she would still finish behind in pledged delegates, her odds aren’t that bad.

No wonder Obama surrogates are two-faced about NAFTA and spiteful toward Senator Clinton.

No wonder Camp Obama is so deceitful, and so mean.