Does irrigation reduce migration intentions after drought? Evidence from West Africa
Journal of Development Economics · 2026 · Alix Debray、Lucile Dehouck、Katrin Millock、Ilse Ruyssen
中文摘要
本文考察灌溉是否会缓解西非干旱后的迁移意愿，以回应气候—迁移文献中对就地适应关注有限的问题。我们将盖洛普世界民意调查的个体层面数据，与西非13个国家的地理编码干旱强度数据和基于卫星估算的灌溉覆盖率数据相结合。研究结果表明，干旱会提高农村家庭的迁移意愿，这一影响在干旱地区尤为明显。总体而言，灌溉并不能抵消这一效应；在控制冲突、汇款、援助以及采用其他干旱和灌溉度量指标后，该结果依然稳健。然而，在长期干旱条件下，灌溉覆盖率开始发挥作用，并对不同收入群体产生不同影响：灌溉缓和了最富裕家庭由干旱驱动的迁移，但对其他群体没有显著影响。因此，灌溉很少能替代迁移成为适应干旱的方式，反而揭示了应对气候压力的就地适应与基于流动性的应对之间是如何相互关联的。
Abstract
This paper investigates whether irrigation mitigates migration intentions following drought in West Africa, addressing the limited focus on in situ adaptation within the climate – migration literature. We combine individual-level data from the Gallup World Poll with geo-referenced drought intensity and satellite-based estimates of irrigation coverage across 13 West African countries. Our findings show that drought increases migration intentions among rural households, especially in arid regions. Irrigation does not generally offset this effect, a finding robust to controls for conflict, remittances, aid, and alternative drought and irrigation measures. However, irrigation coverage becomes relevant under prolonged droughts and affects income groups differently: irrigation moderates drought-driven migration for the richest households but has no significant impact on other groups. Irrigation thus rarely substitutes for migration as an adaptation to drought, but instead reveals how in situ and mobility-based responses to climate stress are interlinked.