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- Количество слайдов: 13
Chapter 14 Renewable Common-Pool Resources: Fisheries and Other Commercially Valuable Species
FIGURE 14. 1 Relationship between the Fish Population and Growth
Underlying Assumptions • Assumptions of the economic model are: • price of fish = constant (price-taker) • marginal cost = constant. • amount of fish caught per unit of effort is proportional to the size of the fish population.
3 Possible Solutions • 1. Open (unregulated) Fisheries (Ec) • Catch until total costs exceed revenues (up to zero profits) => ATC(Q) = Tot. Rev(Q) = P*Q • 2. Maximum Sustainable Yield(MSY) (Em) • Largest “harvest” that can be sustained every year (harvest = replacement rate) • Biologist solution • 3. Economically Efficient (Eo) • Maximize Economic Value (MC(Q) = MR(Q)
FIGURE 14. 2 Efficient Sustainable Yield for a Fishery
• Raising the real cost of fishing through regulation is another policy option. • Raising the marginal cost of effort results in a lower harvest and higher stock sizes. • While the policies may result in an efficient catch, they are inefficient because the efficient level of catch is not caught at the lowest possible cost. • Technological innovations have lowered the cost of fishing, offsetting the increases imposed by regulations.
Policy Options • Command Control (Regulation) • Set Quota for number of fish that can be caught • • • Ignores differences in costs/efficiency of fishermen Can lead to over capacity (too many boats, too big) Discarded catch/by-catch issues • Tradable permits (ITQs) • • • Determine optimal “harvest” and number of licenses to be issued Divide quota/target by number of license = #fish caught per license Auction or grandfather licenses Allow owners to trade (one-year, or multi-year) Multi-species/by-catch • Taxes • Per unit tax on the #fish caught
Individual Transferable Quotas (ITQs) • An efficient quota system will have the following characteristics: • The quotas entitle the holder to catch a specified volume of a specified type of fish. • The total amount of fish authorized by the quotas should be equal to the efficient catch level for that fishery. • The quotas should be freely transferable among fishermen.
• Taxes also raise the real cost of fishing, but do so in an efficient manner. • Unlike regulations, the tax can lead to the static-efficient sustainable yield allocation because the tax revenues represent transfer costs and not real-resource costs. • Transfer costs involve the transfer of resources from one part of society to another. • For the individual fisherman, however, a tax still represents an increase in costs.
FIGURE 14. 7 Effect of Regulation
TABLE 14. 1 Countries with Individual Transferable Quota Systems
Subsidies and Buy Backs • One of management options to reduce overcapacity. • Payments used to buy out excess fishing capacity are useful subsidies, but if additional capacity seeps in over time, they are not as effective as other management measures.
• Marine protected areas and marine reserves areas that prohibit harvesting and are protected from other threats such as pollution. • Marine protected areas are designated ocean areas within which human activity is restricted. • Marine reserves protect individual species by preventing harvests within the reserve boundaries.
d6a3297ef46ce73aa68d9e7c6a80a663.ppt