How would open borders benefit those of us who are already here? You could just as well ask, “How would equal rights for blacks benefit whites?” or “How would equal rights for women benefit men?” The answer, in all three cases, is the same: A mind – white or black, male or female, native or foreign – is a terrible thing to waste. Despite the bipartisan popularity of immigration restrictions, these laws trap most of mankind’s skill, determination, and ingenuity in countries that cripple these precious assets.

The losses boggle the imagination. According to economists’ standard estimates, letting anyone take a job anywhere would roughly double global production – a bigger gain than any other economic reform known to man. This isn’t trickle-down economics; it’s Niagara Falls economics.

Immigrants are rarely charity cases. On some level, even immigration’s harshest critics know that immigrants come to work. That’s why critics favor strict enforcement of the many draconian laws that bar foreigners from the labor market. Syrian refugees will take some time to get on their feet, but they, too, will eventually find jobs as long as their host countries permit them to work.

Countries with lavish welfare states have more to worry about, but there is a cheap, humane alternative to exclusion: restrict migrants’ eligibility for benefits.