so mike bloomberg is 7 times more likely to be teh gop nominee than chris dodd is to be the dem nominee?
umm. no.
Relative pricing of near-zero probability events is not likely to be reliable. For starters, what's the volume there? And, in any case, the price differences are pretty small in absolute terms. I would say that, for all practical intents and purposes, both are (correctly, in my opinion) viewed as having pretty much zero chance of winning their parties' nomination. I would disregard pretty much all numbers below 4 or 5 as just noise.
