The sea crossing from Libya to Italy is one of the world's most dangerous and politically contentious migration routes, and yet over half a million people have attempted the crossing since 2014. Leveraging data on aggregate migration flows and individual migration incidents, we estimate how migrants and smugglers have reacted to changes in border enforcement, namely the rise in interceptions by the Libyan Coast Guard starting in 2017 and the corresponding decrease in the probability of rescue at sea. We find support for a deterrence effect in which attempted crossings along the Central Mediterranean route declined, and a diversion effect in which some migrants substituted to the Western Mediterranean route. At the same time, smugglers adapted their tactics. Using a strategic model of the smuggler's choice of boat size, we estimate how smugglers trade off between the short-run payoffs to launching overcrowded boats and the long-run costs of making less successful crossing attempts under different levels of enforcement. Taken together, these analyses shed light on how the integration of incident- and flow-level datasets can inform ongoing migration policy debates and identify potential consequences of changing enforcement regimes.
翻译:从利比亚到意大利的海上过境是世界上最危险和政治争议最大的移民路线之一,然而,自2014年以来,已有50多万人试图通过这一过境点,利用关于总体移民流动和个别移民事件的数据,我们估计移民和走私者如何对边境执法变化作出反应,即利比亚海岸警卫队从2017年开始拦截事件增加,海上救援概率相应下降。我们发现支持威慑效应,即中地中海路线沿线的未遂过境下降,以及一些移民替代西地中海路线的转移效应。与此同时,走私者调整了他们的战术。我们利用走私者选择船只规模的战略模式,估计走私者如何在发动过量船只的短期付款与在不同执法级别下降低过境尝试成功率的长期成本之间进行交易。加在一起,这些分析揭示了事件和流动层面数据集的整合如何为正在进行的移民政策辩论提供信息,并查明改变执法制度的潜在后果。