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by vy8vWJlco
4733 days ago
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I get your point, but promoting a tax to get the most out of the market is doublespeak. A carrot ("This is better because... and you can use it!") is more "free-market" than a stick ("Don't do that.") - even if I would prefer not to be tempted (or threatened) by either. |
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The basic idea is that some actions you could perform impose costs on people who aren't consenting parties to the transaction. E.g., if Widgets, Inc. dumps the waste from producing widgets into a river, this imposes a cost on everyone downstream.
This would make their widgets cheaper—they're only paying part of the cost of the widget (the folks downstream are paying the rest). With a lower price, they'll sell more widgets.
Markets thus tend to overproduce (vs. what is socially optimal) things with externalities.
There are a couple of ways we take to solve this problem. When the externality is high enough, we prohibit it. E.g., we prohibit murder.
When the externality effects few enough people, and is of a suitable size, they can actually negotiate and resolve it themselves. E.g., if Widgets, Inc. wanted to take water from that river instead of polluting it, thus depriving the downstream farmers of some irrigation, maybe they'd be OK with that for a payment of $X/mo. By making them consenting parties to the transaction, it is no longer an externality, and Widgets, Inc. is now paying the full cost of producing widgets.
Of course, when the externality hits a lot of people, each for a small amount (e.g., air pollution), negotiation is impossible. That leads to the final option:
Do your best to calculate the size of that externality. Then impose that cost as a tax. This is called a Pigovian tax, and also has the effect of making Widgets, Inc. pay the full cost of producing its widgets.
Externalities do not have to be negative; they can be positive as well (e.g., you could clean up a public park). Markets tend to under-produce these, and a similar argument suggests offering a Pigovian subsidy.
Obviously, administering and complying with taxes is not free, and that limits the applicability of Pigovian taxes and subsidies.
Wikipedia has more: http://en.wikipedia.org/wiki/Pigovian_tax