Aviation expert Arnold Barnett on Airline Security Effectiveness

Arnold Barnett, a leading expert on aviation safety and a professor at MIT Sloan School of Management, has applied statistical techniques to study the effectiveness of the security measures in place at U.S. airports.

By Daintry Duffy

April 01, 2004 — CSO — Arnold Barnett, a leading expert on aviation safety and a professor at MIT Sloan School of Management, has applied statistical techniques to study the effectiveness of the security measures in place at U.S. airports. We spoke to him about the successes and failures of post-9/11 airline safety and the hidden dangers of teddy bears.CSO: What did you find in your analysis of airline security?Arnold Barnett: We can sometimes estimate the cost of a security measure, but it's harder to know the benefits. For example, airline agents used to ask those simple security questions at check-in"Has anyone unknown to you asked you to carry an item? Has your luggage been out of your immediate control?" They stopped asking because they said a terrorist would never admit to those questions. But that doesn't mean they weren't useful. Last summer, a 9-year-old kid was given a teddy bear by a stranger at a hotel in the presence of his mother. When he walked through the security check, they found Teddy contained a loaded gun. Luckily it didn't contain plastic explosives, which they can't detect. If the boy's mother had been asked that question, she might have said, "You know, someone did give us something." If you believe time is money, then asking those questions isn't free. But the calculations I've done suggest the terrible price we would pay if a terrorism attempt was successful. What is your view of the current state of airline security?To say that terrorists could easily defeat [our security measures] is overly harsh. But security is far from impregnable. I saw a story that claimed that the lack of recent terrorist events is proof that the security works. Well, there hasn't been terrorism against seaports either, and there's lots of concern that the screening there is minimal. Secretary of Homeland Security Tom Ridge said that the recent flight cancellations involving planes from Europe probably prevented a terrorist attack. If that's true, that would be encouraging. But without evidence, I don't know if one can call the lack of terrorist attacks a success. What about cargo security?For a while after 9/11, they wouldn't allow heavy U.S. mail on passenger airplanes, but now they have resumed carrying mail greater than 1 pound, subject to canine detection. The detection rates are pretty gooddogs have an 80 percent chance of detecting an explosive. But when someone drops off a package weighing more than

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