NBER Working Papers · 2026 · Brian Greaney、Joseph S. Shapiro、Katherine R.H. Wagner
中文摘要
我们研究了全球3400个含水层中许多含水层的人类地下水开采的最优性，在这些含水层中，制度或市场失灵可能产生非最优的开采决策。我们利用遥感数据和经济数据，为每个含水层估计了一个地下水开采的动态模型，反推出使观测到的地下水开采合理化的贴现因子，并将其与拉姆齐基准和市场基准进行比较。五分之三至五分之四的含水层开采速度快于最优水平，使含水层现值下降数个百分点，并造成数万亿美元的现值福利损失。通过补贴或优先占用权无限期保证用户获得恒定水量的政策，或对未来开采完全贴现的政策规则，会产生更大的福利成本。一种永远维持当前蓄水量的可持续开采路径所产生的福利显著低于最优开采路径，因为大多数含水层储量本已处于低效偏低水平。
Abstract
We study the optimality of human groundwater extraction from many of the world's 3,400 aquifers, where institutional or market failures may produce non-optimal extraction decisions. We use remote sensing and economic data to estimate a dynamic model of water extraction for each aquifer, recover the discount factor that rationalizes observed groundwater extraction, and compare it against Ramsey and market benchmarks. Three- to four-fifths of aquifers are extracted more rapidly than is optimal, decreasing aquifer present value by several percent, and creating trillions of dollars in present value welfare losses. Policies that guarantee users constant water quantities indefinitely, through subsidies or prior appropriation, or policy rules that fully discount future extraction, generate larger welfare costs. A sustainable extraction path that maintains current fill forever generates meaningfully lower welfare than the optimal extraction path, because most aquifer stocks are already inefficiently low.