This post originally appeared in Symposium Magazine.
The politics of security are difficult. If you are in favor of security, you must be in favor of more spending on security, or on anything that will “keep us safe.” If politicians or bureaucrats oppose a proposed security measure and something happens, they will be blamed. Security ratchets up quickly. Ratcheting down can only really be by attrition.
Although the increase in security spending post–9/11 exceeds $1 trillion over ten years, the Department of Homeland Security has systematically failed to study the costs and benefits of proposed security measures, most notably radiation scanners. Other Western countries have had similar spending increases.
The problem is not just the total, which is large and might be spent in other sectors. The problem is the allocation within the security sphere. If you have $1 trillion to spend, what is the best way to do that to maximize security? The idea of opportunity cost rises again and again, and is never properly dealt with.
Rather than assessing both the probability of an outcome and its cost if it occurs, the agency has dealt with risk qualitatively, imagining worst-case scenarios and engaging in what the legal scholar Cass Sunstein calls “probability neglect.” The artifice of travelers removing shoes and belts, unpacking suitcases, pouring out liquids, while agents frisk grandmas and children at security checkpoints has been called “security theater” because it aims to give travelers the impression that something is being done to improve security, when there is no evidence any of this has made a difference.
The vector of attack from 9/11, hijacking planes and crashing them into buildings, has been unrepeated not because TSA has ensured safety. Instead, secured cockpit doors and the willingness of passengers to take action in the event of a threat on board has prevented this from occurring. Other attack vectors that remain are receiving less protection because so much money is spent in response to the previous attack. While the TSA monitors security, the lines leading up to security are managed by the airport or airlines themselves, and the latter give priority to certain passengers (e.g., first class), even though they pay exactly the same amount of security tax as everyone else.
This has some analogy with HOT lanes; the key difference is that the car in the HOT lane pays more money to go faster, while in this case, first class passengers only paid more money for a better seat on the plane. Security is not just an issue on airplanes. Inter-city buses and high-speed rail sometimes have security measures, though rarely as stringent. Intra-city public transit generally does not, because it would quickly become unworkable. As a consequence, these other modes are much more vulnerable, as shown in the Madrid attacks (2004), London attacks (2005), or the Tokyo Sarin gas attack (1995).
Security is the enemy of efficiency. Just as with safety, we want perfect security. That goal is unattainable, and security providers should rationally trade off between value of time and value of life.
Excerpted and adapted from The Transportation Experience: Second Edition, by William Garrison and David Levinson (Oxford University Press, 2014)