Re: poly: Immunization (was: libertarianism)

From: Perry E. Metzger <>
Date: Tue Feb 17 1998 - 13:03:00 PST

Robin Hanson writes:
> These categories of "public" vs. "private" good are subtle.

Okay. The definitions I've heard for a public good are usually:

1) Non-excludability
2) Non-rivalrous consumption.

Now, obviously, vaccine is *not* non-rivalrously consumed -- if I am
vaccinated, the same ampuole cannot be used to vaccinate someone
else. Also, ignoring (for the moment) the question of what happens if
90% of people are immunized, at low percentages of immunization, my
benefit is fully excludable -- if I am immunized, it benefits *me*
first and foremost, because *I* will not be sick.

This is in contrast to, say, missile defense for a metropolitan area,
which is non-excludable because all in the area are protected whether
they pay or not, and non-rivalrous in consumption.

BTW, I get flu shots every year, at personal expense, because I
perceive a personal benefit to getting them.

> There is definitely an externality when people infect each other with
> contagious diseases. However, if people could cheaply detect when they
> had been infected and by whom, and if the guilty party could pay damages,
> then tort law could be sufficient to deal with this externality.

Why do we care about this side of it? Isn't the other side sufficient?

If I immunize myself, I will not lose time at work because of illness,
and will not be damaged by it. I therefore have an incentive to be
immunized, exactly as I would have a personal incentive to treat
myself for a disease.

I know many people might not realize this, but MOST PARENTS WANT TO
IMMUNIZE THEIR CHILDREN. There isn't any great horrible problem right
now. Some parents, of course, don't give a damn, but some don't feed
their kids, either. They are the minority. This tends to make me
question whether we have any sort of market failure at all.

Sure, there is an externality here: populations that are "mostly"
immunized will not have diseases spread within them, even to the
non-immunized. However, that is a sort of minor free rider problem --
if enough people do it, people suddenly get an incentive to immunize
themselves when illness breaks out, and the market will correct
itself. It appears that this happens in real life.

We have minor little externalities like this all the time, btw. Most
goods have them. In theory, they are underproduced for this reason,
but in practice, we don't seem to have a problem. As I noted, I see no
evidence for a market failure in the vaccination business. Given this,
why are we concerned?

Received on Tue Feb 17 21:15:11 1998

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