People who have never tried to write anything often imagine they could crank out a terrific novel if they just took the time to do it. In a similar way, I sometimes indulge in the idle fantasy that I could have been a great ad man if I had been so inclined.

One manifestation of this delusion is that I'll edit TV commercials in my head even as I'm watching them. For example, Volvo has a new ad campaign based on the idea that "human life is the greatest luxury of all," or some such nonsense (in fact, economists have determined that rich Corinthian leather is the greatest luxury of all).

One of the campaign's commercials features a petite woman of Asian ethnicity walking across a dark parking lot at night, toward her Volvo S80, which is the only car left in the lot. When she's still a good distance from the vehicle, a device in her hand begins to send off a flashing red light. The woman then turns and hurries away, with a look of concern edging toward panic on her face.

The ad's narrator explains the flashing device is a Personal Car Communicator, which has the ability to sense the heartbeat of any occupant of the Volvo S80 from a distance. Thus if someone has broken into your car and is hiding in the backseat, you'll be made aware of this circumstance before Nancy Grace makes you famous by providing nightly coverage of your abduction and murder.

As they say in the academy, this is indeed a rich social text. My favorite touch is the use of a petite Asian woman, who symbolizes fragility, vulnerability, intelligence, and perhaps wealth. And here's where my brilliant edit of the ad comes in. Check it out: Instead of presenting a fragile flower of the mysterious East as the potential victim of unspeakable atrocities, let's use Shaquille O'Neal!

I know what you're saying to yourself: that this is the most ridiculous idea you've ever heard. But work with me here. Shaq does a lot of ads, and I think we could sell him on this concept. Shaq is a huge black man, so as a social metaphor he functions as the precise opposite of a tiny Asian woman. But he's also perceived as very friendly and charismatic.

To see him hurrying away from his lonely car in a dark parking lot with a look of concern on his face reverses all the viewer's expectations, and emphasizes Volvo not only understands that Life Is the Greatest Luxury of All, but also that All of Us Are In This Together. Or something.

OK, I'll stick with my day job. But the serious point in all this is that Volvo, like many other social actors, is profiting from our extraordinarily irrational attitude toward risk. The risk people face from intruders lurking the back seat of their cars in dark parking lots is so infinitesimal it can't even be calculated.

By contrast, the risk they face from driving those cars can be calculated quite readily, and is astronomically higher. The average American faces a lifetime risk of dying in a car accident of about one in 80. That risk can be lessened a bit by taking certain precautions (like being rich enough to buy a Volvo S80), but it nevertheless remains true that our chances of dying in a car crash is probably hundreds, and possibly thousands, of times higher than our odds of being killed in, for example, a terrorist incident.

In short, buying a Volvo - that cliched symbol of liberal privilege in general and the automotive tastes of academics in particular - is for some people what supporting the Iraq war is for others. In each instance, one is buying the illusion of protection from largely imaginary risks, while at the same time engaging in behavior that increases the real risks Americans run in a significant way.

Paul Campos is a professor of law at the University of Colorado. He can be reached at paul.campos@colorado.edu.