The tradeoff between technology and prescreening intelligence in checked baggage screening for aviation security

The Transportation Security Administration believes selective screening of aviation passengers may result in better security at airports in the United States. Under selective screening, passengers are prescreened using passenger information to determine the degree of risk that each passenger poses). This degree of risk is then used to determine the amount of security resources appropriate for that passenger. How to determine this degree of risk and the information that should be used are controversial topics, as evidenced by the large amounts of discussion concerning CAPPS and Secure Flight. This paper examines selective checked baggage screening systems that use a prescreening system and two types of baggage screening devices, one to screen checked baggage of passengers perceived as lower-risk and the other to screen checked baggage of passengers perceived as higher-risk. This paper reports a cost-benefit analysis of such selective checked baggage screening systems. The analysis is performed for several scenarios that consider various levels of accuracy of prescreening systems in assessing passenger risk. The results indicate that the accuracy of the prescreening system in assessing passenger risk is more important for reducing the number of successful attacks than the effectiveness of the checked baggage screening devices at detecting threats when few passengers are classified as higher-risk. Moreover, several selective screening scenarios are identified that may be preferable to current checked baggage screening strategies.