对极端气温的应对：移民网络与来自萨尔瓦多的国际移民
Responses to Extreme Temperatures: Migrant Networks and International Migration from El Salvador
American Economic Journal: Economic Policy · 2026 · [{"name": "Ana Maria Ibáñez", "affiliation": ["Inter-American Development Bank"]}, {"name": "Juliana Quigua", "affiliation": ["University College London"]}, {"name": "Maria Jimena Romero", "affiliation": ["Cornell University"]}, {"name": "Andrea Velásquez", "affiliation": ["University of Denver"]}]
中文摘要
我们发现, 暴露于极端温度会显著增加来自萨尔瓦多的国际移民, 该国近四分之一的人口居住在美国。极端温度降低了玉米产量, 促使生产者减少收获后投入品的使用并降低对农业工人的需求。这些收入损失与既有的赴美移民网络相结合, 增加了向外移民。我们的发现表明, 当目的地移民网络强大且迁移在资金上仍可负担时, 国际移民如何成为应对极端温度的一种反应。这一模式并非萨尔瓦多所独有: 全球约有 3000 万个农场处于可获得汇款的低收入环境中。(JEL F24, J15, J23, J43, O15, Q12, Q54)
Abstract
We show that exposure to extreme temperatures significantly increases international migration from El Salvador, where nearly a quarter of the population lives in the United States. Extreme temperatures reduce corn yields, leading producers to decrease their use of postharvest inputs and demand for agricultural workers. These income losses, combined with established US migration networks, increase emigration. Our findings highlight how international migration serves as a response to extreme temperatures when destination networks are strong and migration remains financially feasible. This pattern is not unique to El Salvador: Roughly 30 million farms globally are in low-income settings with access to remittances. (JEL F24, J15, J23, J43, O15, Q12, Q54)