Poster #23 - Climate Maladaptation and the Commons: Groundwater Management in India

• In Event: Friday Poster Reception

Abstract

India is the world’s largest groundwater user, with 90% used for agriculture. Groundwater, however, is a common pool resource, generating a tragedy of the commons that threatens agricultural sustainability. We develop a parsimonious model to show how a popular policy intervention — subsidizing efficient irrigation technology — can exacerbate distortions away from socially optimal groundwater extraction. We test the model's predictions by leveraging geophysical variation in extraction externalities and a $1.35 billion program subsidizing efficient irrigation. Consistent with the model's predictions, the policy's impact depends on the severity of extraction externalities: extraction falls 9.2% in low-externality areas but rises 11.0% in high-externality areas. Low-externality farmers maintain cultivation using less groundwater, while high-externality farmers cultivate more intensively. Finally, the program causes climate-adaptive responses in low-externality areas -- reducing extraction during normal rainfall and increasing it during droughts -- but the opposite pattern in high-externality areas, consistent with climate maladaptation. Our findings illustrate that the same common pool conditions that typically justify an intervention may also determine its welfare implications. 

Authors

• Nikhil Basavappa, Columbia University
  Presenting Author

• Ricardo Pommer Muñoz, Columbia University
  Non-Presenting Co-Author