Not all priors are equally defensible.

There appears to be a lot of Bayesian thumb sucking going on, maybe the first was Eli's duo with Socrates, and, of course the bunnies know that James has been going on about uniform priors, and there is always Andrew Gelman.  Now some, not Eli to be sure, might think that the recent election also gave a strong push to priors and p values and such.  Nate Silver of the NYTimes blog five thirty eight has a book out which is reviewed in Science by Sam Wang and Ben Campbell, who also are in the election prognostication business.  Silver, of course, is another guy with a Bayesian hammer looking for statistical nails and finding them all about.  Eli thought a  couple of paragraphs towards the end capture what the Rabett has been trying to beat into bunnies heads.

Our biggest criticism of the book is that although statistics and Bayesian inference are powerful ideas, they are not a cure all.  In his enthusiasm for the good Reverend, Silver has stuffed a fair bit into the same Procrustean bed.  Silver uses the old fox-hedgehog analogy, saying that foxes (including himself) use many ideas, whereas hedgehogs focus on one subject only.  But here he is a hedgehog with one big idea:statistics.

However, Bayesian reasoning works only if the prior is adapted for the task.  According to Silver, many of today's "half baked policy ideas" could be rectified by Bayesian thinking, but that is only part of the story.  The more difficult task is determining good priors.  Silver rejects bad priors effectively in his own field of electoral forecasting by dismissing much of the noise of political punditry.  In other fields he does not always bring the same critical attitude.

Scientific research is often confronted by political and economic forces that are not always appreciated by nontechnical outsiders.  Silver, somewhat perversely takes climate scientists to task for bringing politics into their work.  If anything climate scientists have been dragged unwillingly into a dispute with political interest groups such as the Heartland Institute.  At this point in history, human-induced global warming is a fact an no longer a matter of disputing probabilities.  The book's extended treatment of scientific fringe figures has the inadvertent effect of giving credence to antiscientific views that fly in the face of experimentation and hypothesis testing on the greenhouse effect dating back to Arrhenius over a century ago.  When Silver, now himself a prominent pundit, depicts a "controversy" he highlights the challenge scientists face in convincing people that carbon dioxide is a pollutant.  Not all priors are equally defensible.