Primer on Externalities---One of the more interesting and relevant concepts in Economics

Here is an excellent blog post that summarizes externalitites, negative and positive,  better than I can do...It is an extension of the blog entry I did just below this one.

I Suppose That This Is One Way To Internalize An Externality, Turbine Edition…(From: Econogirl)

Let me start with a quick recap of the whole externality deal, in bullet-point form:
■Externalities are side effects in a market, i.e. costs and benefits that accrue to people who neither produce or consume a product. For example, pollution is an externality because I am affected by pollution from factories even when I neither produce nor consume the products that they make.

■Externalities can be either negative (as with pollution) or positive (as would be the case if I lived upstairs from a bakery and got the smells wafting into my apartment…though I suppose that would get old quickly).

■When externalities are present, free markets left to themselves don’t produce the socially optimal quantity of a good or service. If there are negative externalities, the free market produces more than is socially optimal because it doesn’t take into account the cost it is imposing on society by producing. If there are positive externalities, the free market produces less than is socially optimal because it doesn’t take into account the benefits it is providing to society.

■In these situations, taxes and subsidies respectively can increase overall welfare because they move production and consumption to the socially optimal level. Taxing or subsidizing in the amount of the externality that a good creates is referred to as “internalizing” an externality, and taxes (and subsidies, I suppose) of this form are called Pigovian taxes.

■Note that it is not necessary for the tax revenue generated to be spent on fixing the externality for this setup to work, since the taxes and subsidies are in this case merely used as a vehicle to move the needle on production and consumption. For example, Pivogian taxes to reach the socially optimal level of pollution do not require that the tax revenue be spent on pollution cleanup, but there is an implicit assumption that the tax revenue is being used for something socially beneficial rather than being flushed down the toilet.

This is usually where the textbooks stop, which means that they ignore a number of relevant subtleties and complications associated with externalities and Pigovian taxes. First off, they act as though calculating the amount of the externality is easy, whereas I am pretty sure there is a shiny new Ph.D. and academic job waiting for anyone who has a good way of figuring this out. I mean, by what dollar amount are you inconvenienced by the pollution resulting from the production of one beanie baby? Yeah, I don’t know either. But wait, it gets even more complicated, since this answer technically depends on the framing of the question- people typically give higher answers to the question “how much would you have to receive in order to tolerate one more unit of pollution?” versus “how much would you be willing to pay in order to make one unit of pollution go away?” And this doesn’t even come near the fact that differences in income and whatnot mean that different people probably give widely varying estimates of this amount.

Even if we could put a dollar amount on an externality, we still need to address a few more things before automatically jumping on the Pigou bandwagon. (Okay fine, there isn’t actually a Pigou bandwagon…but there is a Pigou Club.) When we say that Pigouvian taxes lead to the “socially optimal” level of production, we mean that this level of production is best for society in the aggregate under the assumption that a dollar to me is the same as a dollar to you is the same as a dollar to Bill Gates. (I’m not sure why he is always my scapegoat for these types of comparisons, other than that is has a lot more money that I or probably you do.) This does not mean that *everyone* is better off under a Pivogian tax, just that the winners win more than the losers lose. For example, consider a gasoline tax to internalize the pollution and congestion externalities of driving- those with their gas-guzzling SUVs are certainly worse off, since they have to pay more in taxes than they get in benefits from cleaner air and more open highways. People without cars are better off, since there is less pollution and they aren’t paying the gasoline tax. It is important to note, however, that while they may enjoy some public services that are funded by the tax revenue, they aren’t getting compensated directly for having to put up with the remaining pollution that is still in the air. (I will allow you to make your own judgment regarding whether you’d rather have $1 in cash or $1 in government services, but I think I can guess where this audience is going to come out on that.)
Wouldn’t it be nice then if we could eliminate the governmental middle man and have companies tell people “we’re sorry we @#$! up your air, here’s some cash?” It turns out that that isn’t as unreasonable as you’d think. From The New York Times:

Patricia Pilz of Caithness Energy, a big company from New York that is helping make this part of Eastern Oregon one of the fastest-growing wind power regions in the country, is making a tempting offer: sign a waiver saying you will not complain about excessive noise from the turning turbines — the whoosh, whoosh, whoosh of the future, advocates say — and she will cut you a check for $5,000.

Hm. Theoretically, this should work if $5,000 is an appropriate estimate of the per-household cost of the externality. It probably reduces the number of turbines that the company puts up (since more turbines would mean more noise and thus a higher payout required to get households to comply), and, if the households agree to the deal, their revealed preferences show that they are being compensated adequately for their inconvenience. It’s interesting to note that the article implies that some households were refusing the offer out of principle, since they didn’t like the idea of being bought. (Are you surprised by now that people don’t act like economic robots?) If I were trying to strike this sort of deal, I think I would have approached the households before the turbines went in so that they felt a little more in control of the process.