Transferable Discharge Permits and the Control of Stationary Source Air Pollution: Comment
评论指出，当非污染者可以买卖污染权时，市场可能无法达到最优污染水平，实际均衡取决于许可证数量，可转让许可证仅能保证以最低成本维持既定污染水平。
The example demonstrates the difficulty of using marketable pollution rights to achieve an optimal level of pollution. When the presence of a pollutant introduces nonconvexities into the production sets of nonpollutors who are allowed to buy and sell permits, there will be no unique competitive equilibrium in the market for pollution rights. The actual equilibrium will depend upon the number of permits issued and need not represent the optimal pollution level. As Tietenberg argued in his original article (1980), transferable discharge permits can be shown to be efficient only in the sense of providing a least-cost method of maintaining a given level of pollution. 5 references, 1 figure.