Over the past three decades, migrant destination states of the Global North have increasingly sought to co-opt migrant origin/transit states of the Global South to assist with migration management and stop migration flows. This form of international cooperation has been called the “externalization” of migration control, as destination states seek to push their borders outward and stop individuals from ever reaching their recognized frontiers “irregularly” without any prior authorization or vetting. Certain externalization policies, such as the European Union (EU)-Turkey Statement, EU-Libya Coast Guard cooperation, the Italy-Albania deal, and the United Kingdom (UK)-Rwanda agreement, among others, have garnered significant media attention and controversy. Policymakers have presented externalization policies as compatible with legal commitments to providing humanitarian protection to refugees and essential to stopping unsafe and “irregular” migration. In contrast, human rights organizations have condemned such policies, arguing that they prevent individuals fleeing violence and persecution from seeking asylum.

But what are the actual effects of externalization policies on migration flows? Do these policies achieve their intended goals? Importantly, do they have different effects on individuals fleeing violence and persecution (i.e. likely to obtain refugee status) as opposed to individuals migrating for other reasons?

In our new paper in Population and Development Review, we tackle these questions, developing a novel strategy to quantitatively assess the differential impacts of externalization policies on migration flows. We specifically analyze “irregular” flows to Europe during the 2010s and the impacts of the EU-Turkey Statement of March 2016, a paradigmatic example of externalization, and one which policymakers have claimed played a significant role in attenuating the 2015 European migration crisis. This policy promised Turkey six billion euros in humanitarian aid and visa liberalization for Turkish nationals traveling to the Schengen Area in exchange for Turkish efforts in stopping irregular crossings into Greece. The parties also agreed that Syrians who crossed into Greece would be returned to Turkey, and for every returnee a Syrian would be resettled directly from Turkey into the EU.

In our analyses, we use data from Frontex on “irregular/illegal border crossings” (IBCs) and from Eurostat on first-instance asylum adjudications across 31 European destination states (the EU-27, Iceland, Norway, Switzerland, and the United Kingdom). The Frontex data indicate the number of times states have identified an individual crossing their borders without authorization and are organized into nine different “routes” to Europe. As we demonstrate in a related article recently published in International Migration Review, these data are frequently cited by (mainstream) media, international organizations, researchers, and beyond, and represent both individuals who will likely obtain asylum given their nationality (who we label “likely refugees”) and those unlikely to be granted protection (“likely irregular migrants”). In addition, using Eurostat data, we calculate a weighted average asylum acceptance rate by nationality, given the number of asylum applications adjudicated by each destination country per nationality. This allows us to split the data on IBCs, which indicate the nationality of the person associated with each crossing, into our two categories of “likely refugees” and “likely irregular migrants,” and to assess the potential differential impacts of externalization policies.

In line with existing qualitative research, we anticipate that externalization policies which increase the costs of travel across single specific routes have distinct impacts on our two migrant categories. On the one hand, we expect that likely refugees would be primarily blocked by such policies, while likely irregular migrants would be deflected to alternative routes. We posit that this would be the case given that likely irregular migrants have both greater flexibility in their choice of route (they are not fleeing immediate violence and persecution) and greater incentives to adjust (they are more likely to believe that policies could negatively impact their ability to reach their desired destination).

Through a descriptive analysis of flows coupled with an event study of the impact of the EU-Turkey Statement, our results confirm these expectations. Looking at flows across all routes from 2009-2020, we find that nationalities associated with large percentages of likely refugees tend to be highly concentrated on single routes to Europe. Likely irregular migrants, in contrast, can be either highly concentrated (as is the case for Albanians and Tunisians) or highly dispersed across multiple routes (as is the case for Moroccans and Cameroonians). This variation indicates that likely irregular migrants may be more prone to changing the routes they take to reach their desired destination.

In turn, we show that, in the twelve months following the adoption of the Statement, the aggregate number of IBCs identified on the Eastern Mediterranean route (representing crossings from Turkey into Greece) declined, while the number on the Central Mediterranean route (the closest alternative representing crossings form Libya into Italy and Malta) rose dramatically. Breaking this down, we find the geographical shift was driven almost entirely by likely irregular migrants, while refugee crossings declined on the Eastern Mediterranean route without an equivalent shift.

Our findings indicate that the EU-Turkey Statement could be considered a triple failure. First, instead of stopping irregular migration, likely irregular migrants were deflected to alternative routes. Second, Syrians appear to have continued to cross to a certain extent, despite limitations on their ability to obtain protection in Greece. Third, very few Syrians were resettled in Europe from Turkey. Thus, the policy undermined humanitarian protection while failing to stem the migration flows it explicitly aimed to reduce.

Overall, our research shows that externalization policies harm individuals fleeing violence and persecution while failing to stop “irregular migration” to destination states. This raises doubts about whether such policies align with the legal commitments state have made to provide humanitarian protection. Looking ahead, more research is needed to examine the effects of other types of externalization policies on migration flows.