When Two Wrongs Make a Right: Second‐Best Point‐Nonpoint Trading Ratios
推导了在许可证数量不可控时，点源与非点源污染交易的最优次优比率，并用萨斯奎哈纳河流域的数值例子说明该比率与现行比率一致但理由不同。
Abstract Most research on point‐nonpoint trading focuses on the choice of trading ratio (the rate point source controls trade for nonpoint controls), although the first‐best ratio is jointly determined with the optimal number of permits. In practice, program managers often do not have control over the number of permits—only the trading ratio. The trading ratio in this case can only be second‐best. We derive the second‐best trading ratio and, using a numerical example of trading in the Susquehanna River Basin, we find the values are in line with current ratios, but for different reasons than those that are normally provided.