John Mueller and Mark Stewart

John Mueller is a political scientist at Ohio State University and a senior fellow at the Cato Institute. Mark Stewart is an engineer and risk analyst at the University of Newcastle in Australia. They are the authors of Terror, Security, and Money: Balancing the Risks, Benefits, and Costs of Homeland Security and of the forthcoming Chasing Ghosts: The Costly Quest to Counter Terrorists in the United States.

More from TIME
More From TIME