Johns Hopkins University, School of Advanced International Studies, Washington, USA.
Cornell University, Department of Economics, Ithaca, USA.
Nat Commun. 2024 Oct 5;15(1):8654. doi: 10.1038/s41467-024-52858-6.
Dwindling groundwater supplies threaten food security and livelihoods. Output subsidies for farmers are a ubiquitous agricultural policy tool, yet their contribution to growing groundwater stress remains poorly quantified. We show how output subsidies guaranteeing the purchase of crops at higher than market prices may have contributed substantially to declining water tables in India. Our analysis suggests that these policies may have led to a 30% over-production of water intensive crops. In the northwestern state of Punjab, rice procurement can potentially account for at least 50% of the groundwater table decline over 34 years. In the central state of Madhya Pradesh, wheat procurement adopted in the late 2000s appears to have driven a 5.3 percentage point increase in dry wells and a consequent 3.4 percentage point increase in deep tubewells. These results suggest that well-intentioned but poorly designed subsidies can impose harmful externalities on the environment and undermine long-term sustainable development.
地下水供应不断减少威胁着粮食安全和生计。对农民的产出补贴是一种普遍存在的农业政策工具，但它们对地下水压力不断增加的贡献仍未得到充分量化。我们展示了保证以高于市场价格购买农作物的产出补贴，可能是导致印度地下水位下降的主要原因。我们的分析表明，这些政策可能导致了耗水作物的过度生产，其比例达到 30%。在印度西北部的旁遮普邦，在过去 34 年里，大米采购可能至少占地下水位下降的 50%。在印度中央邦，2000 年代后期采用的小麦采购政策似乎导致了干井增加 5.3 个百分点，深管井增加 3.4 个百分点。这些结果表明，尽管初衷良好但设计不佳的补贴可能会对环境造成有害的外部性，并破坏长期可持续发展。
