First of all, base rates matter. Here's a simplified proof: Suppose you want to know if X is true. You have evidence E which is correlated with X - suppose A =

First of all, base rates matter. Here's a simplified proof: Suppose you want to know if X is true. You have evidence E which is correlated with X - suppose A = P(E|X) > 0.5 and B = P(!E|!X) > 0.5. Bayes rule shows: P(X|E) = P(E|X) P(X) / P(E) = P(E|X)P(X) / (P(X)A + (1-B)P(!X)) = P(X)A / (P(X)(A+1-B) + 1-B) Differentiating this w.r.t. P(X) shows that it monotonically increases with P(X). QED. Now I'm not disputing - at all - that human biases exist. Far from it! What I'm asking is whether the behaviors discovered in this article are biases (errors that result in worse decisions) or merely accurate use of priors (using correct base rate knowledge to make better decisions). In the case of orchestras the answer is pretty clearly yes. Similarly in the case of baseball. In college admissions and lending the answer is likely to be no [1]. This article completely ignores the question! [1] https://randomcriticalanalysis.wordpress.com/2015/05/16/on-concentrated-poverty-and-its-effects-on-academic-outcomes/ https://randomcriticalanalysis.wordpress.com/2015/05/16/on-c... http://ftp.iza.org/dp8733.pdf http://ftp.iza.org/dp8733.pdf https://randomcriticalanalysis.wordpress.com/2015/11/22/on-the-relationship-between-negative-home-owner-equity-and-racial-demographics/#my_analysis https://randomcriticalanalysis.wordpress.com/2015/11/22/on-t...