Risk and economic assessment of expedited passenger screening and TSA PreCheck

The Transportation Security Administration’s PreCheck program allows airline passengers assessed as low risk to be directed to faster screening lanes. The paper assesses the scenario of a terrorist plot to down an airliner with a passenger-borne bomb. There are four main conclusions. First, we find that the layered system currently in place reduces the risk of such an attack by 98% - and probably by quite a bit more. Second, this level of risk reduction is very robust: security remains high even when the parameters that make it up are varied considerably. In particular, because of the large array of other security layers, overall risk reduction is relatively insensitive to how effective checkpoint screening is. Third, under most realistic combinations of parameter values PreCheck actually increases risk reduction, perhaps up to 1%, while under the worst assumptions, it lowers risk reduction by some 0.3%. Fourth, the co-benefits of the PreCheck program are very substantial: by greatly reducing checkpoint costs and by improving the passenger experience, this benefit can exceed several billion dollars per year. We also find that adding random exclusion and managed inclusion to the PreCheck program has little effect on the program’s risk reducing capability one way or the other. TSA PreCheck thus seems likely to bring efficiencies to the screening process and great benefits to passengers, airports, and airlines while actually enhancing security.