It's not always possible to gather better information - sometimes all we have is base rates. Furthermore, even when we do have other information, combining othe

It's not always possible to gather better information - sometimes all we have is base rates. Furthermore, even when we do have other information, combining other information with base rates yields a superior result. If you don't agree, by all means write down a distribution and an objective function, and show me decision process that is better than the Bayes optimal decision rule. (Hint: you can't. http://www.ee.columbia.edu/~vittorio/BayesProof.pdf http://www.ee.columbia.edu/~vittorio/BayesProof.pdf Or for a simple example illustrating why, consider the first 20 slides of this presentation: http://www.slideshare.net/webanalisten/chris-stuccio-data-science-conversion-hotel-2015 http://www.slideshare.net/webanalisten/chris-stuccio-data-sc... )