By some estimates, TSA scanners miss as many as 70 percent of banned items that passengers bring to security checkpoints.
The TSA is taking issue with the figures, but isn’t bothering to put out its own numbers.
The Economist points out:
Surely if TSA screeners were doing much better in covert testing, the agency would be eager to release the data. That hasn’t happened. You don’t have to be a cynic to think that the current, unreleased numbers might not be quite as impressive as the agency would like.
Also worth pointing out — there has not been a single successful terrorist attack even with all the contraband that makes it onto airplanes. This is because terrorism is rare. It just doesn’t cost very many lives compared to other threats.
These greater threats include automobile crashes (40,000 deaths per year), heart disease (616,067 deaths in 2009), and cancer (562,875 deaths in 2009). Terrorist attacks, on the other hand, are twenty times rarer than deaths by lightning strikes.
If policymakers were rational, they would give twenty times more attention to lightning strike prevention than to terrorism. But they aren’t, and they don’t. That means the TSA’s $8.1 billion budget, by using up resources that would save more lives elsewhere, will continue to cost more lives than it saves for the foreseeable future.