The case for immigration: the secret to economic vibrancy.

• Author: Legrain, Philippe

There is a contradiction at the heart of our globalizing world: while goods, services, and capital move across borders ever more freely, most people cannot. No government except perhaps North Korea's would dream of banning crossborder trade in goods and services, yet it is seen as perfectly normal and reasonable for governments to outlaw the movement across borders of most people who produce goods and services. No wonder illegal immigration is on the rise: most would-be migrants have no other option.

This is perverse. Immigrants are not an invading army; they are mostly people seeking a better life. Many are drawn to rich countries such as the United States by the huge demand for workers to fill the low-end jobs that their increasingly well-educated and comfortable citizens do not want. And just as it is beneficial for people to move from Alabama to California in response to market signals, so too from Mexico to the United States.

Where governments permit it, a global labor market is emerging: international financiers cluster in New York and London, information technology specialists in Silicon Valley, and actors in Hollywood, while multinational companies scatter skilled professionals around the world. Yet rich-country governments endeavor to keep out Mexican construction workers, Filipino care workers, and Congolese cooks, even though they are simply service providers who ply their trade abroad, just as American investment bankers do. And just as it is often cheaper and mutually beneficial to import information technology services from Asia and insurance from Europeans, it often makes sense to import menial services that have to be delivered on the spot, such as cleaning. Policymakers who want products and providers of high-skilled services to move freely but people who provide less-skilled services to stay put are not just hypocrites, they are economically illiterate.

From a global perspective, the potential gains from freer migration are huge. When workers from poor countries move to rich ones, they too can make use of advanced economies' superior capital and technologies, making them much more productive. This makes them--and the world--much better off. Starting from that simple insight, economists calculate that removing immigration controls could more than double the size of the world economy. Even a small relaxation of immigration controls would yield disproportionately big gains.

Yet many people believe that while the world would gain, workers in rich countries would lose out. They fear that foreigners harm the job prospects of local workers, taking their jobs or depressing their wages. Others fret that immigrants will be a burden on the welfare state. Some seem to believe that immigrants somehow simultaneously "steal" jobs and live off welfare.

Governments increasingly accept the case for allowing in highly skilled immigrants. The immigration bill before the Senate would tilt U.S. policy in that direction, establishing a points system that gives preference to university graduates. Such skills-focused points systems are in vogue: Canada and Australia employ one; Britain is introducing one; and other European countries are considering them.

For sure, as the number of university graduates in China, India, and other emerging markets soars in coming decades, it will be increasingly important for the United States to be able to draw...