Cost-benefit analysis of airport security: Are airports too safe?

• Risk and cost-benefit methods are used to assess the cost-effectiveness of counter-terrorism security measures at airports.
• Fatality risks from terrorist attacks to airports are extremely low, and 100–1000 times less than acceptable risks.
• Attack probabilities would have to be much higher than currently observed rates of attack to justify protective measures.
• Adding curbside blast protection and blast-resistant glazing is the most cost-effective protective measure.

This paper assesses the risks and cost-effectiveness of measures designed to further protect airport terminals and associated facilities such as car parks from terrorist attack in the U.S., Europe, and the Asia-Pacific area. The analysis considers threat likelihood, the cost of security measures, hazard likelihood, risk reduction and expected losses to compare the costs and benefits of security measures to decide the optimal security measures to airports. Monte-Carlo simulation methods were used to propagate hazard likelihood, risk reduction and loss uncertainties in the calculation of net benefits that also allows probability of cost-effectiveness to be calculated. It is found that attack probabilities had to be much higher than currently observed to justify additional protective measures. Overall, then, it is questionable whether special efforts to further protect airports are sensible expenditures. Indeed, some relaxation of the measures already in place may well be justified.