It&#x27;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.<p>If you don&#x27;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.<p>(Hint: you can&#x27;t. <a href="http:&#x2F;&#x2F;www.ee.columbia.edu&#x2F;~vittorio&#x2F;BayesProof.pdf" rel="nofollow">http:&#x2F;&#x2F;www.ee.columbia.edu&#x2F;~vittorio&#x2F;BayesProof.pdf</a> Or for a simple example illustrating why, consider the first 20 slides of this presentation: <a href="http:&#x2F;&#x2F;www.slideshare.net&#x2F;webanalisten&#x2F;chris-stuccio-data-science-conversion-hotel-2015" rel="nofollow">http:&#x2F;&#x2F;www.slideshare.net&#x2F;webanalisten&#x2F;chris-stuccio-data-sc...</a> )