3 April 2008
The Economist recently had an interesting article on anti-terrorist
spending ("Feel safer now?", March-6 print edition). The piece reports
on research done by Todd Sandler and Daniel Arce on the costs and
benefits of different responses to terrorism (paper here). Terrorism creates a lot
of anxiety but (so the authors say) actually costs few lives and many
counter-measures might be ineffective, e.g. if terrorists just shift
attacks to easier targets in response. Sandler and Arce suggest most of
their spending scenarios are not cost-effective, but that political
cooperation could be worthwhile.
Not being an expert in this area, I suspect that the counterfactuals
involved must be extremely hard to defend given the scope of
transnational terrorism. Similarly the reported bounds are huge and the
underlying numbers should be up for debate. For example while skimming
through, I noticed that didn't see any accounting for psychological
stress of those not directly involved in an attack (e.g. the general
population), nor that of military personnel and families who implement
some of the counter-measures. Any views?
It's a day or so past April 1, but if you haven't seen this post [Edit: link fixed] over at Andrew Gelman's blog, it is worth a look. It's about as good an apologia from a "born-again frequentist" as you are likely to find. An exerpt:
I like unbiased estimates and I like confidence intervals that really have their advertised confidence coverage. I know that these aren't always going to be possible, but I think the right way forward is to get as close to these goals as possible and to develop robust methods that work with minimal assumptions. The Bayesian approach--to give up even trying to approximate unbiasedness and to instead rely on stronger and stronger assumptions--that seems like the wrong way to go.
Fortunately, Gelman's conversion experience appears to have ended after about a day...