Using cost-benefit to evaluate aviation security

Stewart and Mueller's paper, "Assessing the risks, costs and benefits of United States aviation security measures," (published by the University of Newcastle, Australia) does an amazing job of unpicking which post-911 security measures actually work and which ones are showy wastes of money and pocket-liners for slimy government contractors:

Hardening cockpit doors has the highest risk reduction (16.67%) at lowest additional cost of $40 million. On the other hand, the Federal Air Marshal Service costs $900 million pa but reduces risk by only 1.67%. The Federal Air Marshal Service may be more cost-effective if it is able to show extra benefit over the cheaper measure of hardening cockpit doors. However, the Federal Air Marshal Service seems to have significantly less benefit which means that hardening cockpit doors is the more cost-effective measure.


(via Schneier)