Photo: Mike BabcockIn the SuperFreakonomics chapter on cheap and simple solutions, we wrote:
And seat belts, at about $25 a pop, are one of the most cost-effective lifesaving devices ever invented. In a given year, it costs roughly $500 million to put them in every U.S. vehicle, which yields a rough estimate of $30,000 for every life saved. How does this compare with a far more complex safety feature like air bags? At an annual U.S. price of more than $4 billion, air bags cost about $1.8 million per life saved.*
A reader named Rich Merrill writes in with an interesting comment:
In the early 70′s I was employed at Ford, doing bumpers and air-bag (safety car) testing.? There is another factor that may need to be considered to get an accurate picture of air-bag effectiveness. In order to work well, the occupants must be belted into place.? The air bag doesn’t keep people in place, it just cushions them when they are flailing around at the peak of the impact. And, of course, there are secondary impacts that occur after the air bag has deflated, so belts are?also important for that “post-bag” event.
So, if the current seat belt usage is about 80%, there are 20% of the people riding around with less than optimal air-bag protection.? I’m not sure how you’d measure it, but this would raise the air bag statistics a bit.
Something you might want to put in future editions?
Note: I’m not a big air bag fan and I have no dog in this fight.? I’m a retired engineer (5 years) and left the auto business in 1975.? I agree completely with your comparative “dollars-per-life” analysis.? Simple solutions are just plain hard to “sell.”? Maybe because nobody is making a profit on them? (Pat-downs vs. $canners at airports?)
*See Levitt and Porter, “Sample Selection in the Estimation of Air Bag and Seat Belt Effectiveness,” The Review of Economics and Statistics 83, no. 4 (November 2001).
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Well, if it’s more complex and mandated by the government, it has to be better, right? Right?
I have a million dollar idea for safety: An exploding foam grenade.
A portable canister placed centrally in a compartment that automatically deploys with rapid deceleration. On triggering it fills the passenger compartment with quick-expanding rapidly-hardening foam. You unpack the passengers like Christmas fruit from Harry and David. It can travel with you and be easily redeployed or retrofitted to any old vehicle.
Unless you think there is a way to cost-effectively get those last 20% of drivers to wear their seatbelts, this information does not change the economic analysis. The cost per life saved under “ideal” circumstances (i.e., everyone buckles up; everyone stops at red lights; nobody texts while driving) have no bearing on reality.
Another thing to consider: when it comes to airbags and seatbelts, the net cost per life saved is probably higher: there are a number of studies (including, I believe, at least one referenced in this blog) showing evidence that seatbelts and airbags decrease fatalities but increase risky driving behavior.
Does this analysis take into account health care costs for reduced injuries when airbags deploy in non-fatal accidents?
I’ve read the Levitt and Porter paper. I don’t see where the $4 billion figure comes from, and –let me take a wild guess– the figure is wrong.
Dollar values of this sort need a paper by themselves to support them.
Regarding crash injuries. I was in a crash where the airbag probably helped. But I wasn’t transported to a Level 1 Trauma Center. So how do you collect the data if nobody dies?
Seatbelts are correlated with a higher risk of lower leg injury in a crash, because nobody would look at your lower legs if you were dead because your head was smashed.
Me? I wanna to be thrown clear…
@drill-baby-drill drill team
Some hollywood types beat you to this idea by almost 20 years. Just such a feature can be seen in the movie Demolition Man circa 1993.
http://www.youtube.com/watch?v=RnyhkBU1yaw
Air bags are intended to save vehicular occupants who aren’t wearing seat belts, and are thus an atrociously expensive “idiot-proofing” feature of your current automobile. Having driven a Subaru into a tree, or rather having desperately tried, and failed, to direct said Subaru around the tree in question, I can tell you that air bags deploy as advertised. Being an EMT who has seen things none of you want to see, you can bet your life that I was wearing my seat belt. Amazingly, the car only suffered moderate damage, and the insurance company elected to repair it. The replacement of the air bag cost four times as much as my first car, a 1965 Beetle.
The data source cited is ten years old. I would question the accuracy of the cost numbers (“annual US price of more than $ 4 billion”) for airbag systems and components for that reason.
The cost of technology in general has come down over the last ten years.