Survivorship Bias

a form of cognitive bias

associated with this image/meme

But dubious?

• Wald did important mathematical work on survivability. But in 1943. Why is this important? By the time it was completed and reported, the final operational versions of the B-17 and B-24, after getting hammered over Berlin and Schweinfurt &c, were already flying, with essentially the same protection (self-sealing gas tanks and selective armour) that they used for the rest of the war. And where is said armour?
• Stephen Stigler (son of George, and a statistician at the University of Chicago) called my attention to a note by W. Allen Wallis himself in which he mentions Wald's work explicitly in connection with survivorship bias. Wallis' original article in the Journal of the American Statistical Association was followed by two very brief comments and then by a further 'rejoinder' of a bit more than one page.