The Transportation Security Administration has repeatedly been dinged by critics, including the Government Accountability Office, for taking a scattershot approach to air travel security. The TSA is notorious for buying equipment and signing on to approaches without ever fully investigating the efficacy of its shiny new toys, and without effectively deploying what it has acquired. Now the RAND Corporation, that grand-daddy of all think tanks, has turned its attention to the issue in an effort to determine not just approaches that improve the safety of air travel, but those that do so cost-effectively. Not surprisingly, its report concludes that much of what the TSA does may well be counterproductive. (Note: the Reason Foundation's own Robert Poole contributed to the study.)
One of the impressive tasks attempted by the authors of Efficient Aviation Security: Strengthening the Analytic Foundation for Making Air Transportation Security Decisions (PDF) is to consider inconvenience costs and annoyances inflicted on passengers above and beyond easily quantified dollar amounts. These are important because:
[V]arious researchers have documented changes in passengers’ preferences and behaviors regarding use of the air transportation system, at least in part due to the increased “hassle factor” associated with new security measures ...
Meaning, there's some evidence that many people are avoiding air travel because they don't enjoy that little taste of East German nostalgia they associate with the process. This sort of analysis necessarily gets a little subjective, but it logically concludes that relatively invisible procedures — like inspecting checked luggage — piss people off less than in-your-face security, and that the total annoyance caused by layers of security is greater than the sum of its parts (but that layers of security are, nevertheless, important).
So ... What doesn't work? For one thing, relying on technological fix-alls, like scanners and sniffers.
[T]he introduction of body scanners may lead transportation security officers or behavioral detection officers to be less attentive in identifying unusual behavior or as vigilant in searching. ...
The introduction of body scanners could cause security screeners to feel that they do not need to be as vigilant and can therefore shift more of their attention to increasing throughput or better interactions with passengers. This could reduce their ability to detect dangerous materials.
Also, while layers of security can improve the chances of detecting threats, they can also annoy passengers to the point that everybody starts displaying warning behavior.
For example, the prospect of being subjected to enhanced pat-downs may raise the anxiety or agitation level for all passengers, which would make it more difficult for behavioral detection officers to detect the anomalous behavior characteristics of potential terrorists.
Another way security elements could interfere with each other is if an element requires more resources than anticipated, for example, by generating a large number of false alarms. Resolving these alarms would create a burden on security staff that could reduce their effectiveness in operating other security elements.
The scientists among you will recognize the phenomenon of observation changing the nature of what is being observed.
The report also points out the important point that, as you increase the number of TSA officers and others involved in security, you also increase the likelihood that one of those insiders will prove to be a threat.
The RAND report does suggest that some approaches may be effective. These include, despite their high cost, Federal Air Marshals — both for deterrence and for their ability to react to events on the scene. Ultimately, the study stops short of saying that air marshals are cost-effective, because that depends on an unknown: how many attacks they've deterred.
The report's authors also favor trusted traveler programs.
While proponents of a trusted traveler program often focus on the convenience benefits to the passengers holding such status, trusted traveler programs also present the potential for security benefits. The screening resources that would be freed from screening trusted travelers could instead be applied toward screening the general passenger population.
For anybody looking for a firm "do this, don't do that" approach to air travel security, Efficient Aviation Security is a little frustrating. The report is short on bullet points and firm recommendations. But, by at least giving some thought to how security procedures should be assessed and what might or might not work, it's way ahead of the people actually patrolling the airports.
Now, if somebody would just assess the value of not shoving one-security-approach-fits-all down our throats.