I think it's what they call the tragedy of the commons.

Wikipedia says an externality "imposes a negative effect on an unrelated third party". For example, pollution from a coal-fired power plant that pollutes the air of people living somewhere else.

Someone who pumps a watershed affects it for miles around, where presumably other people live and are negatively affected by reduced water supply.

Water rights in California are not at all market based, because of historical reasons and a previously mistaken notion of property/mineral rights.

> imposes a negative effect on an unrelated third party

yes, and i'd argue that is certainly the case here.

but the two are closely related.

http://ipeatunc.blogspot.com/2011/08/negative-externalities-...

i think the above is a bit over the top for my taste:

> Secondly, is it really clear that people in Bangladesh (say) have a rights claim to an climate environment that is not two or three degrees warmer than it is right now? How did they acquire this right?

... because yes, I'd say they do have that right, but the point about the expectations being tied to some kind of property rights [physical or fundamental] as a differentiating factor seems to be a strong one.

here they describe the tragedy of the commons as a specific sub category of negative externality (in direct contradiction to the preceding link):

http://web.mit.edu/11.203/www/econ/index.php%3Fid=14.html

You can argue that some ongoing tragedy of the commons also has externalities.

But is there such an externality in the use of water? Is there some side effect that doesn't involve the use of water itself? Isn't the tragedy, the depletion of the supply, the problem? That isn't external.

we're just quibbling here...

> You can argue that some ongoing tragedy of the commons also has externalities.

sure, two of the preceding opinions [wikipedia, mit], argue that the tragedy of the commons is a specific type of negative externality, rather than the other way around. one [north carolina] gravitates more towards your interpretation.

the fundamental issue remains though: our conception of time and consequence is woefully limited in scope.

I think I get it. The low cost is itself having a destructive effect. People, eventually, can't get the resource that is depleted. I just didn't register that as external, but it is if you consider the depleted future to be external to the wasteful present.

An important point, actually, if I understand correctly. Thanks.

That's not really correct. The GP is essentially describing standard price rationing of resources. Negative externalities occur when some activity or transaction imposes costs on some external party that has nothing to do with that activity or was not a participant to the transaction.

EDIT: To put it another way, if 'depleting a finite resource' is considered to be imposing a negative externality, then pretty much every act of consumption generates negative externalities. While I guess we can define it like this if we want, it turns it into a pretty uninformative concept.

Makes sense to me.

Thanks for externalizing that.