As usual, I’m later than everyone else, so I’m just now getting around to reading Freakonomics by Steven Leavitt and Stephen Dubner. The book grew out of an article for the New York Times Magazine by journalist Dubner about economist Leavitt. Leavitt (who is here at the University of Chicago) is a rising young star in the profession, who had previously garnered considerable publicity for his work showing the real reason behind the dramatic drop in crime rates during the 1990’s. It wasn’t stricter enforcement, or a better economy, or innovative policing strategies; it was Roe v. Wade. Leavitt argues that the availability of abortions prevented a large number of childred from being born to mothers who didn’t want them or were unable to take care of them, and that these at-risk kids are exactly the people likely to commit crimes as teenagers. The theme of the book, if there is one, is the attempt to tease out the counterintuitive structures of incentives and pressures that lay behind a wide variety of patterns in our daily lives. And there is, of course, a blog.
But I was happy to see a mention, if only very briefly in passing, of an issue I’ve long wondered about: the relative safety of air travel vs. automobiles. It’s a well-worn piece of wisdom that, despite the potential for spectacular accidents, air travel is actually safer than car travel. I’ve never been quite sure how seriously to believe this claim, since it was never spelled out how “safer” was being defined.
The facts are the following: many more people die in auto accidents each year in the United States (about 40,000) than in airplane crashes (less than 1,000). But that certainly doesn’t answer the question by itself. People spend a lot less time in airplanes than in cars, on average. In fact, it turns out that your risk of death per hour is about the same in a car as in a plane.
So, what’s the answer? Does that mean that air travel and auto travel are about equally dangerous?
No, of course not. Nobody plans their trips by saying “I would like to spend x hours traveling today.” (At least, putting aside the infrequent trips we take purely for the pleasure of being in a moving vehicle.) Rather, there is some place we want to go — i.e., some distance that must be traveled. So the correct figure of merit is the risk of dying per given trip that you’d like to take, not per hour. Airplanes, of course, travel much more rapidly than cars do, so we spend less time in the plane than in a car for a given journey. In this case, the conventional wisdom is true — air travel really is safer.
Leavitt and Dubner don’t actually mention that point, but it’s a crucial feature of risk assessment, or for that matter all sorts of planning. When you are trying to weigh the merits of different ways of allocating resources (money, safety, or whatever), we always have to ask “per what?” That is to say, it’s the rate of resource expenditure that matters, not the instantaneous value. If I want to spend $500 on a spiffy new espresso machine (and I do), I shouldn’t simply say “Wow, that’s a lot of money” — I should carefully compare the cost of the machine plus coffee beans to whatever I’d be paying in small installments at my local Starbucks over the life of the machine. It’s the cost per cup of coffee that matters, not the one-shot price.
Or am I just trying to talk myself into something?
Hmmm. It’s not like you to need talking into something like that.
Call me an evil temptress, but I say go for it. No reason to delay gratification. Cost is not the only factor; you have to assess how much pleasure you will get. ; )
Not that you need much cajoling, but there are trade-offs in opportunities. Coffee shops provide venues for people watching, discovering your music isn’t an edgy as you thought, or trying new coffees. On the other hand, making coffee at home can be faster, save wear and tear on your shoes, allow you to accumulate multiple caffeine buzzes without queuing up, and give party guests reason to “oo and ah.”
Seriously, all those undergrad micro economics courses just convinced me to weigh factors without direct monetary value more heavily sometimes.
This year there is another factor in the car/plane debate. I travel extensively in the summer months; mostly up and down the west/left coast producing music festivals and rock concerts. Over the last few years i have had ample time to make these sorts of correlative analysis: between time in vehicles on ground versus time using vehicles in the air. There is a disproportionate amount of time spent moving no where when travelling by plane while there is a disproportionate amount of time spent slowly progressing in a ground vehicle. For example, i make several trips(all on Tuesdays) between Sacramento and Portland. Disregarding whether i need to use a vehicle at either end point(that is highly dependent upon other factors not involved in this) the trip of 600+ (604)miles will take roughly ten hours on the ground and a little less than five using air transit(2 at airport, 1.7 travelling, another 30+min exiting w/ baggage pickup–all assuming no delays or snags). For many years the cost of airfare was significantly greater than the cost of ground use(including fuel, maintenance, insurance, food and rest stops etc.). I could travel for less on the ground than i could in the air, and use the ground travel time to facilitate business and pleasure. This summer that changed. The cost of fuel began to increase substantially, while the cost of airfares sank to garner riders as airlines suffered one economic setback after another. Even using a hybrid car on one trip from Spokane to Berkeley cost more(fuel $47, food $29, ins {one day rate} $4, maintenance {1100miles=1/3 of 3000 mile use} $28: total $108) than the return flight on the plane($64); the planes(change in portland) took 3.6 hours while the hybrid took a whopping 15 hours. If airlines continue to survive and do not need to price themselves out of business, then air travel will remain a cheaper more efficient form of travel.
Dude!
Definitely trying to talk yourself into something, but I have no clue why. Capital investment is good is with the right. Controlling your own means of production is good with the left. Get your get-wired machine.
Oh and …
when you do the calculation, factor in that by this time next year an expresso will cost $10 at Starbuck’s.
-r
“these at-risk kids are exactly the people likely to commit crimes”
Oh God, that has got to be the *ultimate* PC quote. So it’s the *kids* who are at-risk, not the people who get mugged or whose homes get burglarized? That’s a classic, it really is.
Meanwhile, if aborting these pieces of garbage in proto-human shape is what is reducing crime rates, then I think we have finally found a way of selling abortion rights to the Right. In fact, I hope that the Bush administration will start offering incentives for abortion to…ummm…”at-risk” pregnant women ASAP. “Abortion Rights NOW! — it’s a matter of Law and Order!” Trouble is, though, that we will get liberals opposing abortion rights on the grounds that it discriminates against the “at-risk”……
So it’s the *kids* who are at-risk
Yes, it’s the kids who are at risk of being raised by incompetent mothers.
not the people who get mugged or whose homes get burglarized
Nobody said that those people weren’t ALSO at risk (of something else). *cough cough straw man cough*
Yes, more people die in car crashes than in airplane crashes. But how many of those 40,000 a year are drunk drivers (or passengers of a drunk driver); sleep-deprived drivers; poor drivers (teenagers or senile); risk-takers (driving during a snowstorm or speeding) etc.
And sure there’s always that rare story of the family of 5 innocently taking a drive to grandma’s who get flattened by a garbage truck, but I would guess that a careful driver who always wears his seat-belt has less of a chance of dying in a car crash than we’re led to believe.
“Or am I just trying to talk myself into something?”
That depends: is this machine going in your house, or your office? If it’s the later you absolutely should buy it.
I don’t know about you, but for me the choice usually isn’t “What do I prefere: Sitting one hour in the car or one hour in the plane (or train for that matter)?” I don’t do this for the comfy seats but because I want to get to X. My car being old, pure travel time in the car is much longer than by plane. So you should compare deaths per km (or mile) rather then per hour.
And I forgot: Most car accidents happen close to your home and not on long distance travel. So you should take the plane to work and the car for cross country travel. Hmm. Except that planes crash during start and landing and rarely mid-flight. So, these comarisons might be even more difficult.
“Nobody plans their trip by saying “I would like to spend x hours traveling today”.
Perhaps not, but you might say “This trip would take 36 hours so I skip it”. The amount of time we spend traveling remains more or less constant in all cultures. People who walk may travel a shorter distance than those who fly, but on average they don’t spend more time doing it. This isn’t really that strange, who would take a vacation in Bermuda if it took a month just to get there? If people didn’t have cars you would have denser population so that people had to travel a shorter distance to work. Invent a faster way of traveling and people will travel further. Thus the per hour figure of risk is just as relevant as the per km one.
Don’t bother. Everyone knows the best espresso in Chicago is already at the U of C (in Ryerson, across the hall from the barn).
anon
Hmm. Any single travel taking 150 years has, independently of the transportation system, a death rate of 100%. This should be accounted in the equations somewhere.
Another quickfact: if automovile crashes do for a 1.7% of the yearly death toll (just estimating, I haven got actual XXIth century data) than a average driving time of 25 minutes/day should met the statistics even in the case of perfect conduction, just because you are living a 1.7% of your life inside the car.
The real problems with cars are beyond death toll; it is about the whole economics around them, which we need to keep fueling (indeed) in order to keep an stable civilisation. Think not only about petrol & gas, but also the car market, the factories, the repair workshops etc… what percentage of a countrie economy comes directly from car transportation? A lot of countries even get a significant tax income straight from fuel taxes.
My second problem (well, to me the first one) against cars and planes and mystic technology in general is that people is not encouraged to understand the physics and mechanics of the devices they are using daily. This was part of the motivation for my railbike project I mentioned recently. But generically I abominate of these car companies whose ads speak of technology and whose engines are black boxes for specialised personal only. They even use propietary or undisclosed computer interfaces. For our security, sure. Ignorance=security, a classical equation.
When I was younger workshops were in the center of the cities. We kids wandered around doors into the local coffee roaster, got to peer into chemist backoffice, keep looking the sparks from the soldering tool or ckecking how a gear wheel was fitted into its place in a printing mechanism. No wonder why now we need to sell science as if we were, er, car resellers.
A third problem about cars is that they can emphatise individualism and competition. But well, that is another history. Or another rant, which I let for other contributors.
I don’t have the numbers with me but several years ago I also got tired of hearing that cars were much more dangerous than planes with nothing to back up this claim. I looked at this in some detail, digging through the statisics on automobile fatalities, and found that since I am not a male between the ages of 18 and 25, driving late at night while drunk (or riding with a drunk driver) my odds of being killed in a car crash plummetted drastically. (I allowed for the possibility of being hit by a drunk driver in the other car.) The trick was in comparing miles or time of travel in a car with either miles or time in flight. A miles comparison gave me roughly even odds, but I don’t think this is the best way to calculate the relative safety since most plane crashes occur within a short window of time around take-off and landing, so that your odds of dying on a long vs short plane flight do not differ significantly. (I also did not include any planes other than commercial airlines).
If you are sitting in coach on a transatlantic flight (especially from the west coast of the US to, say, Paris) I would claim you are a much higher risk for suicide — add crying babies and the risk is for homocide.
When I was younger workshops were in the center of the cities. We kids wandered around doors into the local coffee roaster, got to peer into chemist backoffice, keep looking the sparks from the soldering tool or ckecking how a gear wheel was fitted into its place in a printing mechanism. No wonder why now we need to sell science as if we were, er, car resellers.
This is what happens with technolgoical advancements.
Trying to keep pace, and seeing in new ways with modern controls, the hands on, takes us away from the intuitive developement that came from doing things the “ole way”:)
While the nostalgia is strong in the heart of our memories, resistance to such changes takes us away from the reality of change?
While these things might now sit in the archives, we need the “older folk” to remind us sometimes of the way it used to be, to realize, that there are always natural processes to be considered even while we are dismayed with such advances.:)
Hi Plato! My nostalgia of the “ole way” is not about the old technologies by themselves, but about an old motivational way we have lost. It is probably happening now for some time, because I remember about a chemistry playset manufactured by a company unrelated to toy industry (they are providers od plastic for General Motors); my guess is that they made the playset as a sort of compensation… as a way of resistance.
Also, it is not exactly that the workshops have dissapeared, it is that they concentrated and moved out the city. A modern solution could be to install university AND secondary school in the same areas that factories and workshops, so al least students would interact natutally with real producers during rest time at the pub. For instance, I would expect that the Open/Free Software movement should easily extend into programmable manufacturing machines. Free Wheels anf gears, downloadable from internet.
For instance, I would expect that the Open/Free Software movement should easily extend into programmable manufacturing machines. Free Wheels anf gears, downloadable from internet
Ah, yes I see. I once dreamed of a molecular feeder. Using your idea then, we could manufacture?:)
Hello Plato. The “molecular feeder”, or “personal fabricator” generalising the “personal computer” is perhaps the ultimate goal behind the Center For Bits and Atoms and their Fab Labs. In a humbler perspective, during a speech on free software someone pointed out to me that modern lathes, millers, shapers and general drill tools are automatised and that they use pretty standard formats to describe the pieces. But companies keep closed the information on tolerances in order to fight third-party production of parts.
In a humbler perspective, during a speech on free software someone pointed out to me that modern lathes, millers, shapers and general drill tools are automatised and that they use pretty standard formats to describe the pieces. But companies keep closed the information on tolerances in order to fight third-party production of parts.
“Industrial designs” are still held in context of copyright or trade marks, yet I think the advancement of anything becoming “quite common” has it’s reproductive value eventually found in the cheapest production wise somewhere. Hate to be undercut in original design?
I have seen these computerized lathes before, just not with microprocessing abilites. Very interesting.
The ‘meeting hall” is a interesting version of native design? The Netherlands seems to have more then just Gerard t’ Hooft to consider in their contributions to societies.:)
Alejandro Rivero:
If the travel took anywhere near 150 years, and it was a group tavelling (as on a plane) it would also have a birth rate. This should also be accounted for in the equations.
I don’t think very many babies are born in airplanes. Although perhaps it would be more fair to count conceptions.
indrax, good point!!! 😀
(Plato, could you ellaborate, here or in your weblog, about Netherlands “meeting hall” concept? I went lost somewhere your discourse path)
Rivero,
What’s in a House?
That’s all.