under my umbrella

"I would like to know whether it is likely to rain tomorrow. However, when I ask an Everett follower, all she will tell me in direct response to my question is that `it will rain and it won't rain.' Nevertheless, she is willing to tell me whether or not it is rational for me to take an umbrella. I suppose that if she tells me that it would be highly irrational for me to take an umbrella, I can take the hint and deduce that it is very unlikely to rain.
However, there does seem something wrong with the fact that she is not allowed to say this directly."

Robert Wald reviewed Many Worlds?: Everett, Quantum Theory, and Reality

efficiency

Cosma writes about power laws and psycho killers; The usual story - somebody sees a power law when e.g. a log-normal distribution would be a much better fit.
This suggests that three toed sloths and the internet are not fully efficient distributors of information.

Meanwhile, on intrade I saw (Jan 24, 8am ET) some interesting odds for the Dow Jones Industrial index, suggesting that markets are not always fully efficient either:
Dow Jones to close ON or ABOVE 11750 on 31 Jan 2012: probability = 91.5%
Dow Jones to close ON or ABOVE 12000 on 31 Jan 2012: probability = 93.0%
Dow Jones to close ON or ABOVE 12250 on 31 Jan 2012: probability = 97.0%

So I wonder about the odds in a cliché betting market...

the isle of Elba

"Frequentists have long been in a kind of exile when it comes to statistical philosophy. ... This may now be changing."

Deborah Mayo has a blog.

on probability

"We take issue with Kent's arguments against many-world interpretations of quantum mechanics. We argue that his reasons for preferring single-world interpretations are logically flawed and that his proposed singleworld alternative to probability theory suffers from conceptual problems. We use a few thought-experiments which show that the problems he raises for probabilities in multiverses also apply in a single universe."
Guildenstern and Rosencrantz in Quantumland

It seems to me that the debate about many worlds has finally reached the point of asking 'what exactly do we mean with probability?' and I doubt this will be settled any time soon.
To be, or not to be, that really seems to be the question...