Thursday, October 21, 2004

Getting It All Wrong about the Risk of Terrorism


Gene Healy points approvingly to an article in Cato's Regulation magazine about the risks of terrorism. According to Healy, the author of the article (one John Mueller)
collects the known knowns and the known unknowns about how much sleep we ought to be losing about dying in a terrorist attack. Mueller's answer: not much. And we ought to spend more time worrying about the risks of overreaction.
Healy then quotes Mueller:
Until 2001, far fewer Americans were killed in any grouping of years by all forms of international terrorism than were killed by lightning, and almost none of those terrorist deaths occurred within the United States itself. Even with the September 11 attacks included in the count, the number of Americans killed by international terrorism since the late 1960s (which is when the State Department began counting) is about the same as the number of Americans killed over the same period by lightning, accident-causing deer, or severe allergic reaction to peanuts....
Although there have been many deadly terrorist incidents in the world since 2001, all (thus far, at least) have relied on conventional methods and have not remotely challenged September 11 quantitatively. If, as some purported experts repeatedly claim, chemical and biological attacks are so easy and attractive to terrorists, it is impressive that none have so far been used in Israel (where four times as many people die from automobile accidents as from terrorism)....

Accordingly, it would seem to be reasonable for those in charge of our safety to inform the public about how many airliners would have to crash before flying becomes as dangerous as driving the same distance in an automobile. It turns out that someone has made that calculation: University of Michigan transportation researchers Michael Sivak and Michael Flannagan, in an article last year in American Scientist, wrote that they determined there would have to be one set of September 11 crashes a month for the risks to balance out. More generally, they calculate that an American's chance of being killed in one nonstop airline flight is about one in 13 million (even taking the September 11 crashes into account). To reach that same level of risk when driving on America's safest roads--rural interstate highways--one would have to travel a mere 11.2 miles....
Why do we "seem" to be relatively safe from terrorism? Might it have something to do with diligent counter-terrorist activities since 9/11 -- both here and abroad -- such as rounding up a lot of illegal aliens and holding them indefinitely?

Does the record of domestic safety from terrorism since 9/11 mean that we're out of the woods? By no means. Eight years elapsed between the first and second attacks on the World Trade Center. We made the mistake of letting down our guard after the first attack, which is why the second attack was successful -- and catastrophic. Who knows what will happen next? Recent history proves that it's idiotic to say that something is unlikely to happen because it hasn't happened yet -- which is precisely what Mueller is trying to say.

It's similarly idiotic to compare the risk of terrorism to such activities as driving a car or flying on a schedule airlines. Terrorism isn't a substitute for those activities -- it's an independent, unrelated act. Terrorism isn't an accident with a fairly predictable probability of occurring. It's a deliberate act committed by implacable enemies, against whom we must be on guard at all times. Being on guard isn't hysteria -- as Mueller would have it -- it's prudence.

If I were still the managing editor of Regulation, I would have resigned rather than abet the publication of Mueller's fatuous analysis.

Tom W. Bell at Agoraphilia has more to say; for example:
...Suppose that because devastating tornados strike your hometown only rarely, your $500,000 house faces a 1/5,000,000 chance of destruction by high winds each year. Although you could prevent that threat by extraordinary measures, such as building a concrete box around your house, you rationally calculate that you should spend no more than a dime a year on tornado protection ($500,000/5,000,000). Suppose further that your hometown faces a 1/5,000,000 chance each year of being devastated by a nomadic warrior tribe. Unlike tornados, however, nomads respond to incentives. Following one such raid, you might happily pay more than a dime towards your town's Marauding Hoard Smackdown fund. You calculate that the temporary expense of chasing down and punishing the nomads will teach them a hard lesson, convincing them to take your town off their "to sack" list. The risk of further such attacks will thereafter drop, repaying your defense investment with future security....
I'm truly surprised that Peter VanDoren, the editor of Regulation, let Mueller's shoddy analysis slip into the pages of his journal.