Sunday December 18 marked International Migrants Day. According to the UN the total number of international migrants increased from an estimated 175 million in 2000 to 244 million persons in 2015. Nearly two-thirds of all international migrants live in Europe or Asia; however migration is now more widely distributed across more countries. Today the top destination countries receive a smaller share of all migrants than in 2000.

The lure of a well-paid job is a powerful driver of international migration. John Kennan, in his article "Freedom of movement for workers," argues that allowing workers to move freely across countries could yield large gains, comparable to a doubling of labor income in developing countries. He says, “Although the immigrant flows would be large, the wage effects would be small since increases in labor supply would induce investment.”

Escaping conflicts is another driver of migration. Providing a safe haven for refugees can be seen as a public good and this provides the rationale for policy coordination between governments. However the volume of applications differs widely across countries and policy harmonization is not sufficient, argues Tim Hatton. He says that “burden-sharing measures are needed as well, in order to achieve an optimal distribution of refugees across member states.”

Explore more IZA World of Labor content about migration policy.

• Freedom of movement for workers by John Kennan
• Setting policy on asylum: Has the EU got it right? by Tim Hatton
• Integrating refugees into labor markets by Pieter Bevelander

• Research conducted by Aarhus University and the University of Copenhagen has found that bullied men are more likely to leave the workplace.
• Governments should do more to tackle mental health issues, according to a new report.
• We're experiencing a movement of unhappiness, says former UK PM David Cameron.
• Almost all jobs created in the US since 2005 are temporary.
• UK net migration remains high at 335,000 in the year to June.

• Does employee ownership improve performance? by Douglas Kruse
• Are happy workers more productive? by Eugenio Proto
• How important is career information and advice? by Sandra McNally
• Childcare expansion and mothers' employment in post-socialist countries, by Anna Lovász
• Privatizing sick pay: Does it work? by Pierre Koning

Visit the IZA World of Labor site for more concise, informative, evidence-based articles across the spectrum of labor economics.