英文文献：On the spatial nature of the groundwater pumping externality-地下水抽水外部性的空间性质
英文文献作者：Brozovic, Nicholas,Sunding, David L.,Zilberman, David
英文文献摘要：
Most existing economic analyses of optimal groundwater management use single-cell aquifer models, which assume that an aquifer responds uniformly and instantly to groundwater pumping. This paper demonstrates how spatially explicit aquifer response equations from the water resources engineering literature may be embedded in a general economic framework. Calibration of our theoretical model to published economic studies of specific aquifers demonstrates that, by averaging basin drawdown across the entire resource, existing studies generally understate the magnitude of the groundwater pumping externality relative to spatially explicit models. For the aquifers studied, the drawdown predicted by single-cell models may be orders of magnitude less than that predicted by a spatially explicit model, even at large distances from a pumping well. Our results suggest that single-cell models may be appropriate for analyses of the welfare effects of groundwater management policies either in small aquifers or in larger aquifers where average well spacings are tens of miles or more. However, in extensive aquifers where well spacings are on the order of a few miles or less, such as many of those of concern to groundwater managers and policy makers, use of single-cell models may result in misleading policy implications due to understatement of the magnitude and spatial nature of the groundwater externality.

大多数现有的最优地下水管理的经济分析使用的是单单元含水层模型，该模型假定含水层对地下水抽取的响应是一致的和即时的。本文演示了水资源工程文献中空间显式含水层响应方程如何嵌入到一般经济框架中。将我们的理论模型与已发表的有关特定含水层的经济研究进行校准，结果表明，通过对整个资源的盆地递减量进行平均，现有的研究与空间显式模型相比，通常低估了地下水抽水外部性的大小。对于所研究的含水层，即使在离抽油机井很远的地方，用单细胞模型预测的下降量也可能比空间明确模型预测的下降量小几个数量级。我们的结果表明，单细胞模型可能适用于分析地下水管理政策的福利效应，无论是在小含水层，还是在平均井距为数十英里或更多的较大含水层。然而,在广泛的含水层的空隙是几英里或更少,如许多地下水管理者和决策者的关注,利用单细胞模型可能导致误导性政策影响由于轻描淡写的大小和空间性质的地下水外部性。