The so-called ‘European Migrant Crisis’ has been blamed on armed conflict and economic misery, particularly in the Middle East and Sub-Saharan Africa. Some have suggested that this process has been exacerbated by climate change and weather events. In this paper, we evaluate these claims, focusing on the role of droughts in influencing irregular migration flows to the European Union. Drawing on temporally disaggregated data on the detection of unauthorized migrants at EU external borders, we examine how weather shocks affect irregular migration. We show that weather events may indeed influence migration. Yet, in contradiction to the findings from recent research, we find no evidence that a drought in a sending country increases unauthorized migration to the EU. If anything, and while not entirely conclusive, the incidence of drought seems rather to exert a negative, albeit moderate, impact on the size of migration flows, in particular for countries dependent on agriculture. Conversely, higher levels of rainfall increase migration. We interpret this as evidence that international migration is cost-prohibitive, and that adverse weather shocks reinforce existing financial barriers to migration.

所谓的“欧洲移民危机”被归咎于武装冲突和经济困境，尤其是在中东和撒哈拉以南非洲地区。一些人认为，气候变化和天气事件加剧了这一过程。在本文中，我们评估了这些主张，重点关注干旱在影响非正常移民流入欧盟方面的作用。利用在欧盟外部边界检测未经授权的移民的时间分类数据，我们研究了天气冲击如何影响非正常移民。我们表明天气事件确实可能影响迁移。然而，与最近的研究结果相反，我们没有发现任何证据表明输出国的干旱会增加未经授权的移民到欧盟。如果有的话，虽然不是完全定论，干旱的发生似乎对移徙流动的规模产生了负面影响，但影响不大，尤其是对依赖农业的国家而言。相反，较高的降雨量会增加迁移。我们将此解释为国际移民成本过高的证据，并且不利的天气冲击加剧了现有的移民金融障碍。