# Cell-phone measurements

-March 01, 2002

If you would like to take a break from electrical measurements, you might look at the controversy surrounding the measurement of the costs and benefits of talking while driving (TWD).

Anecdotal evidence of TWD-related accidents had made me sympathetic to efforts to ban TWD. It turns out, though, that TWD is a good thing: Banning it would cost Americans \$24 billion annually, while affording only a \$1 billion reduction in death and destruction. At least that's the conclusion of researcher Robert W. Hahn and others at the American Enterprise Institute.

It's easier to manually perform a Fourier transform on a digitally modulated time-domain signal than to follow Hahn's calculations. Fortunately, I learned Fourier transforms before computers were widely available to college students, so I decided to give Hahn's figures the once-over. I couldn't find any errors.

Not all are convinced, though. Radio personalities Click and Clack of NPR's Car Talk show have castigated Hahn, taking the sentimental view that human life is priceless. I like that view, but it turns out that there's a spec called VSL (value of a statistical life), and it equals \$6.6 million. Statisticians derive this figure by asking survey questions such as "Would you pay \$300 for an airbag system that cut in half your risk of dying in a traffic accident?"

The math doesn't convince Click and Clack. If you need to call your spouse with a reminder that your child's school play starts in 20 minutes, you can pull over, they say. But wait, isn't that sudden swerve from the fast lane to the berm even more dangerous than making the call at-speed?

Author Steven E. Landsburg tries to sort out the controversy in a January 30 posting to the online magazine Slate, but he adds more heat than light. He calls a Click and Clack comment slanderous, yet he rejects Hahn's \$24 billion figure, placing TWD benefits at \$10 billion. His suggestion? Confiscate the \$10 billion and buy fire-fighting equipment. That, he says, will save five times more lives than are lost to cell-phone-related accidents.

My opinion? Aggressive TWDers are early adopters who will promptly outfit their cars with collision-avoidance radar, thereby limiting adjacent lane interference. Technology will solve the problem long before Click and Clack and Hahn resolve their differences.