While migration occupies a prominent place today in the media and on political agendas, what we are now seeing is likely to be dwarfed by the scale of migration in the future. A 2011 Gallup World Poll found that 40 per cent of people living in the poorest 25 per cent of countries would like to move permanently to another country. This migratory pressure is only likely to build as populations in the developing world continue to grow and the drivers of migration become stronger.

There are two drivers in particular that are worth mentioning. First is the wage-gap in unskilled labour between rich and poor countries. An unskilled worker in Europe or America can earn a wage many times higher than a worker in the developing world doing the same job. This creates a significant incentive for workers to migrate to high-wage countries.

The second driver is the changing demographic profile in advanced economies. Ageing populations and longer life-expectancies increase the need to attract a young workforce from abroad. This need will be intensified by higher demand for labour in so-called “hardcore and low-skilled nontradeable” employment. These are jobs such as janitors and cashiers which cannot be exported overseas, but which are unpopular in rich countries.

International migration has the potential to bring about explosive change to the world economy. Economists estimate the gains from removing restrictions on labour migration from poor to rich countries to be in the trillions of dollars, somewhere between 20 and 60 per cent of world GDP. Such income gains could bring millions of people out of poverty and deprivation.

Just as the potential benefits from unfettered migration are enormous, so too are the risks. Policymakers are facing a backlash at the moment in America and Europe against the relatively modest number of migrants arriving on their shores. The problems caused by this toxic political environment are exacerbated by a lack of external coordination between countries. Dealing with the migration challenges we currently face requires far greater international cooperation. This does not bode well for a world in which migrant flows from developing countries are likely to be many, many times higher.

The dilemma of migration promises to be one of the key challenges of the 21st century. Balancing the opportunities and risks of this disruption will prove a worthy challenge for our brightest future leaders.