The Pendulum Swings Back, and Stops Dead
Changes in airline carry-on restrictions begin September 26

25 Sep 2006 in Regulatory Science

The Washington Post reports tonight that the ban on liquids and gels onboard commercial aircraft will end tomorrow. Travel-size containers will be permitted through the TSA security checkpoint, and items purchased inside the "sterile area" beyond the TSA security checkpoint will be permitted aboard aircraft.

Excerpts from the TSA bulletin are reprinted below.

Post reporter Bill Brubaker writes:

Total regulatory bans are rarely justified on benefit-cost grounds. The risk posed by the activity must be so great that it swamps any conceivable gain from engaging in it. A practical example of a justifiable regulatory ban is the prohibition on driving the wrong direction on interstate highways. (Even then, there are circumstances where one can imagine the benefits still exceed the costs, such as the rescue of critically injured crash victims.)

Under the new rules, passengers must enclose their travel-size toiletries in a clear plastic bag and remove it from their carry-on baggage before passing through security. The government prescribes that this bag must measure 7.5 inches by 8 inches and have a zipper top. A reasonable inference is that TSA has determined that even if liquid or gel explosives were secreted within such containers, too little material would be available to construct an effective explosive device. The problem with this inference is that it's difficult to believe that any such determination was based on research conducted since August 10.

Passengers also will be able to bring onboard beverages and other items purchased within the sterile area. Previously we have pointed out that this particular ban was nonsensical as a risk-based tool and likely to undermine public confidence in TSA:

The problem for TSA (and for air travel security in general) is that overbearing and senseless restrictions are risk communication failures. When TSA imposes rules that appear ridiculous on their face, it causes travelers to discount real risks and doubt TSA's legitimacy and competence. After all, if TSA is unable or unwilling to distinguish real from phantom risks, why should travelers make such distinctions, or have confidence in TSA?

As a risk management matter, appearing ridiculousness undermines the effectiveness of those elements of the security regime that are fully justified, whether on benefit-cost grounds or as prudent exercises of precaution. This inevitably misallocates scarce resources. This problem is severely exacerbated by TSA's unwillingness to allocate its passenger screening resources based on risk-based criteria. No one believes that all airline passengers pose the same threat, yet it is TSA's policy to treat all travelers as if they do.

We predicted that the ban would be relaxed when passengers, in increasing numbers, quietly violated the rules because the rules made no sense intuitively or analytically:

Violations can be expected to be more frequent and less discreet, at which time we predict TSA will abandon the policy stating that it is no longer necessary but never admitting that it was illogical in the first place.

Early on Patricia Reilly Panara ridiculed the restrictions as "the Battle Against Baby Bottles." She titled her post, "The War on Liquids Evaporates Passenger Goodwill," but unfortunately she incorrectly attributed the ban to the airlines rather than TSA -- suggesting that airlines' goodwill could be the victim of TSA's heavy-handedness. Blogs have reported anecdotes of rule-breaking by passengers or warnings about the risk to the airline security system posed by overzealous rules.

When traveling to or from Britain, the rules on liquids and gels are only part of the problem. Between August 10 and September 22, antil All carry-on luggage banned. This has led to comical situations with sensible results that reinforce the concern that bans undermine public support for rational airline security. J. K. Rowling tells the story ("Book 7 Update" under "news")::

The heightened security restrictions on the airlines in August made the journey back from New York interesting, as I refused to be parted from the manuscript of book seven (a large part of it is handwritten, and there is no copy of anything I had done within the US. They let me take it on, thankfully, bound up in elastic bands. I don't know what I would have done if they hadn't; sailed home, probably.

The story was reported by Rob Hinchcliffe in Londonist, on September 14 when he accurately predicted Tuesday's TSA action. Hinchcliffe's tone suggests envy about Rowling's special treatment rather than opposition to the ban on its merits. Both bans undermine public confidence in the competence of governments' airline security systems.

TSA's new instructions include the warning "[t]t is unlikely that additional changes in the liquid, aerosol and gel policy will be made in the near future." The announcement says "experts from around the government, including the FBI and our national labs have analyzed the information we now have and have conducted extensive explosives testing to get a better understanding of [the] specific threat" posed by liquid and gel explosives.

There are two major changes:

1. Travelers may now carry through security checkpoints travel-size toiletries (3 ounces or less) that fit comfortably in ONE, QUART-SIZE, clear plastic, zip-top bag.
2. After clearing security, travelers can now bring beverages and other items purchased in the secure boarding area on-board aircraft.

At the checkpoint travelers will be asked to remove the zip-top bag of liquids and place it in a bin or on the conveyor belt. X-raying separately will allow TSA security officers to more easily examine the declared items.

In addition, larger amounts of prescription liquid medications, baby formula and diabetic glucose treatments must be declared at the checkpoint for additional screening.

It is unlikely that additional changes in the liquid, aerosol and gel policy will be made in the near future.

This security regimen applies to all domestic and international flights departing U.S. airports. Travelers should, however, check with transportation security authorities in their country-of-origin for flights originating at non-U.S. airports.

[add a comment]

Comments on The Pendulum Swings Back, and Stops Dead
Changes in airline carry-on restrictions begin September 26

Add a Comment