If you do not put physical barriers, fish would move across different properties, making overfishing profitable anyway. It is like two “private” oil fields over the same oil reservoir.
Profitable for who? I am thinking companies owning some waters would charge fishing companies proportionally to how much they capture in their waters. Overfishing would eventually lead to no fish being captured in their areas, and therefore no revenue from fishing.
It is the canonical case for an immediate Pigovian tax: the externality is global, uniform, circulates in the atomosfere… Regarding imports, you can charge a carbon tariff.
The increase in the death from non-optimal temperature is not uniform.
If fish move across properties, your own overfishing affects fish density in neighbouring properties. It is like two oil wells extracting from a common reservoir. Of course, both “privatization” and “Coasian bargaining” are better than Pigouvian taxation, but none of this mechanism is necessarily available.
I remind you the entire sequence:
Theorems of welfare economics: under the hypotheses of the theorem all Pareto optimal outcomes can be obtained by market clearing and [tailored] lump sum taxation. Unfortunately, to “lump sum” tax you need private information on productivity, so the best you get is “pareto optimal” with the usual deadweight loss of income taxation.
Property is not perfect: there are externalities. Then you try to use “Coasian bargaining”, for small cases where externalities and property is well defined.
Multilateral bargaining is too complex, or property rights are not easy to establish: Pigouvian taxation on the externality as long is easy to measure and you have some sovereign to impose it.
Now, a funny thing is that on one side you complain on the lack of Pigouvian mechanisms, and then even for the canonical case of the carbon tax, soon you find arguments against it (!). Yes, of course, the total value of the externality is the world average impact of carbon emissions: there are winners and losers. The consensus based on detailed simulation is that the global externality of an additional molecule of CO2 is negative (at least given the current location of human population: given how costly and destabilising is large human reallocation, better not to remove that hypothesis).
Profitable for who? I am thinking companies owning some waters would charge fishing companies proportionally to how much they capture in their waters. Overfishing would eventually lead to no fish being captured in their areas, and therefore no revenue from fishing.
The increase in the death from non-optimal temperature is not uniform.
If fish move across properties, your own overfishing affects fish density in neighbouring properties. It is like two oil wells extracting from a common reservoir. Of course, both “privatization” and “Coasian bargaining” are better than Pigouvian taxation, but none of this mechanism is necessarily available.
I remind you the entire sequence:
Theorems of welfare economics: under the hypotheses of the theorem all Pareto optimal outcomes can be obtained by market clearing and [tailored] lump sum taxation. Unfortunately, to “lump sum” tax you need private information on productivity, so the best you get is “pareto optimal” with the usual deadweight loss of income taxation.
Property is not perfect: there are externalities. Then you try to use “Coasian bargaining”, for small cases where externalities and property is well defined.
Multilateral bargaining is too complex, or property rights are not easy to establish: Pigouvian taxation on the externality as long is easy to measure and you have some sovereign to impose it.
Now, a funny thing is that on one side you complain on the lack of Pigouvian mechanisms, and then even for the canonical case of the carbon tax, soon you find arguments against it (!). Yes, of course, the total value of the externality is the world average impact of carbon emissions: there are winners and losers. The consensus based on detailed simulation is that the global externality of an additional molecule of CO2 is negative (at least given the current location of human population: given how costly and destabilising is large human reallocation, better not to remove that hypothesis).