30 September 2015

I'd Rather Be Lucky Than Good

There's an article on SA, that starts with Abraham Wald, a Brit stat who, during WWII defied the generals. Not a team player, he. The issue was how to re-armor aircraft in order to save them and, more importantly, the flyers. The generals looked at the bullet holes, pointed, and said, "there". Wald also looked and said, "not so much".

What's of interest, beyond the article, is the comments. The gist of which is that, following Wald's thesis, stock picking is foolish, and that inordinant gains are, mostly, just plain luck. You get the market rate of return, period. Unless dumb luck smiles on you.

Which, in turn, raises a question not addressed by either the article or the comments.
Something similar occurs in the investment industry. It claims that some people are extremely skilled, since year after year they've outperformed the market. They'll identify these "investment gurus" and convince you of their abilities. But a simple thought experiment can show that it would be impossible to not have these gurus produced just by luck.

If one goes to the track, and bets on FlapperFluzzy in the seventh, at 40 to 1, and she wins, you get taxed at median income rates, not some capital gains slap on the wrist rate. You got lucky at the track. You don't get an additional tax break.

So, if luck is so much a part of inordinant investment gains, and has even less benefit than playing the ponies, why not revert to the 91% rates of Eisenhower? He of the "fear the military industrial complex"? After all, what else are they going to do with the moolah? Stuff it in a mattress?

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