Comprehensive new databases of migration flows and policy data since World War II highlight how some policies have had unintended effects.

“Much of the migration debate is fact-free and based on unfounded assumptions,” asserts Hein de Haas, Professor of Sociology at the University of Amsterdam. “Thanks to recent advances in research, we have much better evidence to assess the effects of immigration policies on international migration.”

With the DEMIG project, Prof. de Haas, then based at Oxford University, has led a team of researchers in the creation of four unique databases that chart migration flows, policy changes and visa data for the entire post-WWII era. Analysis of this rich dataset is finally shedding light on how immigration policies and regulations have influenced international migration over nearly three-quarters of a century.

“Contrary to popular belief, we have found no global acceleration in migration,” Prof. de Haas says. “The proportion of people migrating is the same as that just after World War II, even though the global population is far greater. However, the changing role of Europe in international migration has been the big game changer: there has been a significant ‘global migration reversal’. In fact, before the War, Europe was the largest global supplier of migrants, and now it is the largest attractor.”

Migration policy: successes and failures

Since 1945, immigration policies have generally become less restrictive, apart from those relating to asylum-seekers and some categories of un-skilled workers, DEMIG data reveal. “Contrary to policy rhetoric, we see that most policies are not designed to affect the numbers of migrants coming in, but select in terms of who can migrate,” Prof. de Haas observes.

Through advanced statistical analyses of the datasets, Prof. de Haas and his colleagues have provided hard evidence showing that migration policies often produce unintended side effects. For example, restrictive policies decrease immigration, but they also interrupt circulation, often preventing migrants’ return and pushing them into permanent settlement. The effect of restrictions on net migration and migrant numbers is therefore ambiguous.

In addition, restrictions often cause migrants to find new migration routes – legal or irregular – as they avoid countries with certain restrictions. And in the run up to the enforcement of a restriction, unplanned migration surges can occur when migrants want to ‘beat the ban’. Such unintended effects pose fundamental dilemmas for policy-makers, and show the need for carefully designed, fact-based policy-making.

Interview: Determinants of international migration (2015)

Adding data to the migration policy debate

The DEMIG project questioned the popular belief of widespread migration policy failure. “Despite the unintended effect of some policies, most migrants migrate legally. Illegal border crossings and refugee migration represent a relatively small share of total immigration,” Prof. de Haas is quick to note.

The five-year DEMIG project ended in 2014 and has seen the publication of many peer- reviewed articles. Four publicly available migration databases – the largest in the world – are receiving great attention from academics around the globe. The European Commission’s ‘Knowledge Centre for Migration and Demography’ will use the DEMIG migration data. The Centre works closely with Prof. de Haas, who regularly contributes to the migration debate, meeting with journalists, policy-makers and politicians to discuss the empirical evidence now available.

“Migration is a highly politicised topic,” he says. “Because migration policy is often about electoral gain and the desire to be seen to take bold actions, politicians don’t prioritise designing fact-based policies.” He concedes that the project’s findings are unlikely to lead to overnight policy change, but is confident the facts will filter through. “The project has added data and insight to the debate” he concludes, “which have a great potential to contribute to more effective policies”.

In a second ERC-funded project, MADE (Migration as Development), Prof. de Haas is now examining how development processes and social transformation shape the geographical orientation, timing, composition and volume of migration. While economic and human development is often believed to reduce migration out of poorer countries, evidence suggests that it rather increases migration.

The project will use theory-building, quantitative tests using international databases, and case studies in six countries to boost understanding of the developmental drivers of migration.

Hein de Haas is a founding member and a former director of the International Migration Institute (IMI) at the University of Oxford (United Kingdom). In 2015 he was appointed Professor of Sociology at the University of Amsterdam. His research focuses on the linkages between migration and broader processes of social transformation and development in origin and destination countries. He did extensive fieldwork in the Middle East and Africa and, particularly, in Morocco. He also maintains a blog on migration-related topics. Twitter: @heindehaas

Find more examples of projects in the brochure: Migration and asylum: The contribution of frontier research to the understanding of human mobility across frontiers