On Mon, Mar 1, 2010 at 11:11 PM, Chris Browne <cbbro...@acm.org> wrote: > Nobody really notices the carnage on the highways, because, > stochastically, there are such a large number of events, both positive > and negative (e.g. - millions of people making it home safely, and a > tiny number that don't) that it's difficult for there to be a > sufficiently large number of "adverse events" to notice.
I don't think the number of positive events factors into it. It's that the law of large numbers kicks in and the rate of death is pretty much constant. Every now and then there's an atypical weekend for a given town or city and the death toll spikes and people do in fact notice. Suddenly the news is filled with stories about the carnage the prior weekend and various imagined causal factors just like when the stock market goes up or down and the news people try to explain why. > People are a lot more worried about terrorists than about car accidents, > even though the latter are *enormously* more likely to cause one's > demise, by a *huge* factor. (This mismeasurement irritates me a lot, > particularly when I visit airports!) Well there is also a difference here. Because there is an active opponent in the terrorism case the security has non-linear game-theory effects. In the car safety case you could spend 10x as much money and reduce accident death rates by 1/10th. But there's a point of diminishing returns and an optimal value somewhere. In the case of terrorism it may well be the case that if you spend any money on security you must spend a lot of money for it to reach the threshold at which terrorists redirect their attacks elsewhere. Earthquakes are of course not in that category. They just occur rarely enough and then our perception of their severity is heavily influenced by where they occur so clumpings are just inevitable. -- greg -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
