What I Learned While Running the New York Marathon

When?I stated on this blog that I was hoping to run the NY marathon in under four hours, I was hoping that my public commitment would spur me on.? And it did.? Sort of.? I ran under four hours – 3:54:59 to be precise – which I’m thrilled by.? So score one for Ian Ayres and?the value of public commitments.
But I think I could have run faster, and my public commitment is to blame.? You see, at mile 20, I realized that I was on target to beat my goal – “all” I had to do was run six more miles at a moderate clip, and I would be a sub-four hour marathoner.? The only thing that could prevent me from getting there was if I “hit the wall.”? So rather than running the last few miles hard, I ran them cautiously, doing whatever I could to prevent my legs from blowing up.? If a runner could play defense, then I was playing it.
There’s an economic lesson here.? I respond to incentives, and the incentive I set up was to beat a specific goal.? But that’s different than committing to run my best race.? And this led to the perverse result that I slowed down over the final miles, rather than running hard.? By picking a specific target, I distorted my incentives, and those incentives led to a good outcome (a sub-four-hour marathon), but prevented me from striving for an even better marathon.
So today the runner in me is left wondering if I could have beaten 3:50. And the economist in me is left wondering how to set incentives that don’t distort effort.