One common complaint about proponents of open borders is that we picture human beings as interchangeable parts.  If an American can do X, so can a Haitian.  Why can’t the open borders crowd see the obvious truth that people are not “plug-and-play” – that you can’t jumble different kinds of people and expect them to function well together?

My instinctive reaction is to appeal to Econ 1 and basic facts. 

The Econ 1: If people of different nationalities worked poorly together, employers would account for this fact in their hiring decisions.  An employer with a 100% native-born American workforce would look at immigrant applicants and silently note, “Oil and water don’t mix.”  Or perhaps he’d think, “Americans and high-caste Indians work well together, but Americans and Indian untouchables don’t.”  Then he’d hire on the basis of these ugly truths, while paying lip service to equal opportunity and the brotherhood of man.  As a result, immigrants – or at least the “wrong kind of immigrants” – would discover that migrating for better jobs is a waste of time.  Jobs are better in the First World, but you have to be First-World-compatible to land one. 

The basic facts: This manifestly is not how labor markets work.  As the opponents of immigration loudly complain, First World employers hire immigrants all the time.  They eagerly hire legal immigrants – and as long as the law is laxly enforced, they furtively hire illegal immigrants.  Even when the law criminalizes non-discrimination, plenty of First World employers look over their shoulders, shrug, mutter “Money’s money” and break the law.  Doesn’t this show that workers ultimately are plug-and-play?

Yet on reflection, my instinctive reaction misses much of the magic of the market.  If you’ve ever been a boss, you know that getting human beings of the same culture to effectively cooperate together is like pulling teeth.  Indeed, it’s like pulling shark teeth that never stop growing back.  The more different the members of your team are, the greater the miscommunication and strife. 

How then do firms manage to function?  The social intelligence of the leadership.  Good managers know in their bones that diverse human beings aren’t built for close cooperation.  Rather than throw their hands up in despair, however, good managers rise to the challenge.  True to their job description, managers manage their workers, forging them into effective teams despite their disparate abilities, personalities, and backgrounds.  It’s an uphill battle, and you have to keep running just to stay in place.  But good managers kindle the fire of teamwork, then keep the fire burning day in, day out.

The critics of immigration are right to insist that people aren’t plug-and-play.  Cultural diversity definitely makes teamwork harder.  Unlike the critics of immigration, however, businesses around the world treat this fact not as a plague, but a profit opportunity.  Sure, some stodgy entrepreneurs mutter defeatist cliches about oil and water and keep hiring within their tribes.  But more visionary entrepreneurs rise to the challenge of diversity every day.  That‘s why even the most unskilled and culturally alien workers rightly believe that the streets of the First World are paved with gold.  Given half a chance, socially adept businesspeople rush to do the paving.

But isn’t the workplace a relatively favorable environment for diversity?  No; the opposite is true.  Stores gladly open their doors to the general public because almost any human being with money to spend is a lovely customer.  As long as the customers don’t bite each other, the more the merrier.  Landlords are a little more selective, but not much: If your credit’s good and you keep the noise down to a dull roar, they’ll rent to you. 

Employers, in contrast, hire with trepidation.  They know that co-workers need to cooperate like the fingers of a hand.  One bad worker makes a whole firm look bad.  One bad worker can ruin a whole day’s work.  One bad worker can make ten good workers quit in frustration.  Outside of the army, no voluntary endeavor in modern adult life is more regimented than the workplace.  Yet by the power of social intelligence, business managers make diversity run smoothly, laughing all the way to the bank.

Where does politics fit in?  It’s a lingering concern, but vastly overrated.  Most immigrants are even more politically apathetic than natives.  They vote at sharply lower rates.  And when they arrive in a vast new land, most of their old grievances become irrelevant overnight: Once they arrive in the U.S., Serbs and Croats, Hutus and Tutsis, even Israelis and Palestinians let bygones be bygones.  Political plug-and-play is unnecessary because few immigrants want to play politics in the first place.