Children play in a makeshift refugee camp of the northern Greek border point of Idomeni, Greece, in May 2016. (AP)

Can foreign aid be used to prevent or slow migration? As the Mediterranean migration crisis continues, some politicians want to tie aid to anti-migration measures. They argue that countries that fail to prevent migration or won’t take back failed asylum seekers should be denied development assistance. Underlying this argument is the assumption that receiving countries should use development aid to create jobs within the country — and thus prevent further emigration.

This argument might appeal to some voters in wealthier countries. But it’s based on a misunderstanding of the relationship between development and migration — and, in particular, a phenomenon called the “migration hump.”

Here’s an explanation. The “migration hump” generally describes how migration tends to increase as households move from poor to middle income — and then tapers off as average household incomes increase beyond middle income.

Our recent policy research points out that continued development aid can mitigate forced displacement in very poor countries, while supporting safe, legal migration. This can lead to positive development and migration outcomes in both developed and developing countries. Thus, a better policy approach would be to use development assistance to reduce the drivers of forced migration and displacement, while supporting safe, regular migration.

Cutting development aid will not stem migration across the Mediterranean

There are two important details to keep in mind when looking at the relationship between development aid and migration. First, much of the research that informs our understanding of economic migration focuses on people migrating through formal processes. The current crisis in the Mediterranean, by contrast, is driven by irregular “mixed migration” flows where incidents of forced displacement from violence are intertwined with voluntary forms of economic migration.

There is still much scholarly debate about the impact of development aid on migration flows, but recent statistical evidence suggests that we see decreases in mixed migration when development aid increases, particularly in poor countries. This suggests aid can mitigate acute drivers of forced displacement, such as food insecurity or a lack of shelter.

Second, macroeconomic changes often take decades to influence migration patterns. Cuts to development aid in a given year aren’t likely to influence short-term migration trends. Michael Clemens looks at the economics of migration, for instance.

He explains that when a country reaches per capita GDP of about $7,000 to $8,000, regular, legal migration stops increasing — people tend to stay put. Assuming a standard economic growth rate, this means a “low income” country such as Niger will take over 100 years to reach the $7,000-per-capita income threshold at which economic migration flattens out, then starts to decrease. In the meantime, the data indicate that mixed emigration from Niger will only increase.

This means changes to the amount of development aid in any single year probably will not lead to noticeable changes in migration from a country like Niger to Europe. Instead, migration trends reflect the fact that people are going to migrate because they feel economically and physically insecure. Punishing a country like Niger for not preventing emigration by withholding aid is unlikely to change those fundamentals, and could make them worse.

What does the “migration hump” tell us about development and migration policy?

There’s an important takeaway: When economic growth leads to migration, both the sending and receiving countries can see positive economic effects, especially if migration is organized in an orderly and safe manner.

This was the case for Germany’s Triple Win arrangement, which started in 2012. Nurses from the Philippines (and later Serbia, and Bosnia and Herzegovina) applied for German work visas through a program organized cooperatively by the German and Philippine governments to mitigate a nursing shortage. The Philippines, a lower-middle-income economy whose per capita GDP grew from $2,581 to $2,951 during the life of the program, had the facilities and capacity to train well-qualified nurses.

The nurses’ migration to Germany temporarily took pressure off the Philippines’ nursing labor market, met a labor need in Germany, and importantly supported skills and financial transfers back to the Philippines.

How does this play out in the African context? Cutting back on development aid to punish countries that don’t stop migration is not likely to slow mixed migration in the Mediterranean region. This is largely because many people are not moving because of increased economic choice. Instead, they seek safety, or leave their homes in response to a total lack of local economic opportunity.

These are the factors that development policy and humanitarian aid are designed to address. In the best case, development aid can mitigate the drivers of forced displacement and mixed migration by reducing the drivers of forced displacement.

If the long-term goal is to reduce forced migration and displacement, and support safe mutually beneficial economic migration, the evidence suggests that increasing development cooperation and humanitarian assistance in Africa is the better way to go.

Charles Martin-Shields is a researcher at the German Development Institute/Deutsches Institut für Entwicklungspolitik (DIE), and tweets at @cmartinshields.

Steffen Angenendt is the head of the Global Issues division at the German Institute for International and Security Affairs.

Benjamin Schraven is a senior researcher at the German Development Institute/Deutsches Institut für Entwicklungspolitik (DIE), and tweets at @Ben_Schraven.