You are bending words like regulation and tax to fit your preconceptions in way that disagrees with how other people understand them. Also, a simple tax can no

You are bending words like regulation and tax to fit your preconceptions in way that disagrees with how other people understand them. Also, a simple tax can not solve the tragedy of the commons for fisheries as long as fishing will remain profitable. Nash equilibrium involving full exploitation remains as long as there is a profit. Fish are not an externality that can be reduced to avoid taxation, but the objective. While cap on fishing will work.