Ah, the stuff we burn! Take fossil fuels, for example. Why do we continue to burn them after all we know about how they strangle the planet? Because they’re still so cheap. Yes, even when it costs $500 a month to heat our houses, burning what we find below the earth’s crust is still cheaper than anything else we’ve discovered to heat space. Or is it? If we factor the actual cost of all the consequences of burning fossil fuels, the health costs and the environmental costs, nobody could possibly afford to shoulder his share of the burden. We don’t pay for those costs in our utilities bills. And until we do, oil and gas and coal will seem cheap.

The same is true for cars versus public transportation. Is it cheaper to drive to New York City than to take the train? It sure seems so, no matter what gas costs this week. But that highway wasn’t free; clearing it of snow isn’t free; patrolling it with state troopers isn’t free; the real cost of gasoline would break anybody’s budget if we really paid its true cost at the pump, and so on. Until we pay the true costs of commodities, we have no clear concept of what’s really “cheap.”

So, what if cigarettes cost $222 a pack? Maybe they actually do cost $222 a pack, but the cost isn’t collected by the Wawa cashier. Maybe if somebody offered to pay a smoker $222 for every pack she didn’t smoke, she’d find the motivation to quit? Freakonomics sheds some light on these questions.

From there, if you wish, you can quickly link to a more general discussion of the Economy of Desire. Any way you enter the counterintuitive world of freakonomics, you’ll find plenty of unexpected causes and effects.