When Water Runs Out: Adaptation to Gradual Environmental Change in Indian Agriculture
利用印度古吉拉特邦40个村庄的地下水枯竭自然实验，研究发现水资源短缺导致灌溉农业减少和城市迁移增加，但仅发生在主导社会群体中，且缺乏节水技术或人力资本投资。
Abstract Increasing water scarcity will affect hundreds of millions of smallholder farmers in coming decades, but little is known about the likely forms of adaptation. This study exploits a natural experiment in which heterogeneous geological formations affect the rate of groundwater depletion across 40 villages in Gujarat, India, to provide novel evidence on this question. The analysis reveals that greater water scarcity leads to widespread declines in irrigated agriculture and enhanced migration to cities, but only among dominant socio-economic groups. No evidence is found of substantial compensating investments in water-efficient technologies or in human capital, despite farmers having long been aware of the decline in water levels.