Division of Labour: Are you spending too much time in airports?

July 26, 2005

Are you spending too much time in airports?

Economist Stephen Landsburg (who writes a nifty column for Slate btw) once wrote that "if you've never missed an airplane, you're spending too much time in airports."

Economists of course get this. When making decisions optimally (i.e., trying to equate marginal benefits and marginal costs), it is rarely the case that the optimal amount of something is zero. In the case of airport waiting, you have to weigh the cost of missing the plane against the cost of getting there too earlier and wasting time. Of course no one wants to miss a plane, but then no one wants to waste time in the airport either. By weighing the expected marginal costs of each against the other you decide how early to leave for the airport. But it seems reasonable that (given the time uncertainty in getting to and through the airport) you should miss a plane here or there.

However, when I say this kind of thing to normal people, they rarely get it. Usually I'm met with a strange look, "Who is this nut?" their faces say.

Anyway, here are few other fun rules to consider:

If you've never had a speeding ticket, you're driving too slow.
If you've never been audited, you're paying too much in taxes.
If you've never been hungover/passed out/puked, you're not drinking enough.
If you've never been fired, you're doing too good a job.
If you've never been slapped by a girl, you're not asking out enough girls.

Comments open if you have your own submissions.

Posted by Robert Lawson at 11:35 AM in Economics · TrackBack (0)

Comments

"If you never get hit by a bus, you're spending too much time looking both ways before crossing the street." (In other words, sometimes the penalties are so asymmetric that you do want all your errors to be in one direction.)

Btw, I'd heard the maxim attributed to George Stigler before Landsburg wrote it down.

Posted by: Lawrence H. White at July 26, 2005 02:13 PM

The Btw comment by Lawrence White is an application of Stigler's Law that "Aphorisms are typically not named after their actual originators." Which begs the question, who came up with Stigler's Law?

Posted by: Mike Ward at July 26, 2005 04:58 PM

Continuing Mr. White's comment:
If you've never had a serious crash, you're driving too slow....
If you've never been in prison, you're paying too much in taxes...
If you've never been convicted of sexual harassment, you're not asking out enough girls...

On the other hand, it seems entirely possible that society on a whole could benefit from some non-zero level of various problems. It may be that more years of life are spent looking both ways than would be lost from the occasional pedestrian death. I see pedestrians being rather ambitious all the time, so they apparently are willing to trade some risk for some time savings. Certainly we use driving speeds to balance travel time with injuries and deaths. If the personal scale does not work, some of these still make sense in the larger scheme of things.

Posted by: Zubon at July 27, 2005 12:13 PM

And my friends thought that I was merely being an ass when I objected to my band director's creed of "to be early is to be on time, to be on time is to be late... don't be late."

Posted by: David Rossie at July 27, 2005 05:53 PM

If you haven't died jumping out of an airplane...

and more of the same as described above. I had in my mind an elegant proof that the statement is incorrect, but I suppose the good folks at Chicago figured out a better proof during a walk down the stairs.

Posted by: Craig at July 28, 2005 02:26 AM

Thanks to everyone for the comments. They are exactly why made the post. The fact is that MC and MB curves often don't intersect in the positive quadrant so the optimal amount (at the individual level) of many things is indeed zero.

In other words, much of life is a corner solution.

Posted by: Bob Lawson at July 28, 2005 08:41 AM