Flu Shot...

Ecnomist Alex Tabarrock just got his flu shot

People who have the flu spread the virus so getting a flu shot not only reduces the probability that I will get the flu it reduces the probability that you will get the flu. In the language of economics the flu shot creates an external benefit, a benefit to other people not captured by the person who paid the costs of getting the shot. The external benefits of a flu shot can be quite large. Under some conditions each person who is vaccinated reduces the expected number of other people who get the flu by 1.5.

Since a large fraction of the benefits of the flu shot, perhaps even a majority of the benefits, go to other people and not to the person paying the costs, the number of people who get a flu shot in the United States is well below the efficient level. I only got the shot because, as you well know, I'm altruistic. I care about you. But do send your checks, that will help.

In lieu of a check I'm thinking of having some buttons made up to encourage people to get their shot. Here are some possible slogans:

Kiss me, I'm vaccinated.
Take one for the herd!
Get a flu shot. The life you save may not be your own.
Madison Avenue here I come!

Of course, we know from the Coase Theorem that there is an alternative approach. We could charge people who do not get their flu shots. (Thus, if you haven't had a shot you must still must send me a check.) Or to reduce transaction costs we could fine people who get the flu. I kind of like that last one. (But what to do about the 36,000 a year who die from the flu - charge their estates?)