# A little snipe at Mr. Chakrabortty

Just three months after the California earthquake of 1989 killed 63 people, injured 3,500 and damaged 100,000 buildings, local students took part in surveys that showed they were highly optimistic about their vulnerability to natural disasters.

I take your main point in the piece: yup, we are over-optimistic….a trait without which there would be no entrepreneurs for example.

However, that specific example isn\’t one of over-optimism. That\’s one of being entirely rational.

The Loma Preita earthquake was 7.1 on the Richter scale. And as you say, 63 killed.

The Haiti earthquake was 7.0 (it\’s a logarithmic scale, so ten times less ene3rgy than the California one) and 230,000 killed.

That\’s pretty good evidence as to why, in California, what with the building codes and all, you might quite rationally be pretty optimistic about your vulnerability to natural disasters.

## 6 thoughts on “A little snipe at Mr. Chakrabortty”

1. The Richter scale is indeed logarithmic – but the progression is less than you state. An increase in 1.0 in scale reflects a ten-fold increase in shaking amplitude – which is equivalent to a 30-fold increase in energy released.

The 0.1 scale difference between the 2 quakes you reference reflects a root-2 difference in energy (i.e. about 41% greater in California than Haiti.)

Of course, the huge difference in casualties justifies your point, even if the California earthquake had been identical or somewhat lower energy – the 3650-fold difference in deaths would, if measured on a mathematically identical scale to the Richter (and my arithmetic is correct) and equating deaths to energy rather than amplitude (questionable) – reflect a scale difference of 2.4 units.

If you equate deaths with amplitude, that would give you a scale difference of 3.6 – close to the difference between Loma Prieta and last night’s wobble in Ripon.

2. Surely the best time to be optimistic about not being killed by an earthquake is straight after one. After all they don’t tend to happen very often.

3. If they weren’t optimistic they wouldn’t be living there.

4. “Ah, Chile. Remember how, during the Social Security debate, Chile’s retirement system was held up as an ideal — except it turned out that it actually yielded very poor results for many people, and the Chileans themselves hated it? Now we have the usual suspects claiming that Chile’s relatively low death toll in the quake proves that — you guessed it — Milton Friedman was right. You see, the Chicago Boys made Chile rich, and that’s what did it.

As a number of people have pointed out, there’s this little matter of building codes. Friedman wasn’t exactly fond of such codes — see this interview in which he calls such codes a form of government spending, because they “impose costs that you might not privately want to engage in”. –

Paul Krugman.

http://krugman.blogs.nytimes.com/2010/03/03/fantasies-of-the-chicago-boys/

5. Doesn’t getting things wrong by an order of magnitude invalidate one from commenting on statistical matters or is that just something for the Guardian?

Tim adds: Ohh, noo, nooo. For a start, they were two orders of magnitude out. And I was only one but on a logarithmic scale, with is only one tenth as bad. So they were definitely elebenty times worse than me.