Under open borders, over six billion people would be free to move to the United States.  The population could increase by more than a factor of twenty.  And under real open borders, there’s no mandatory waiting period.  If everyone wants to move the day the borders open, they’re free to do so.

This seems like a crazy policy.  Imagine the chaos of six billion people migrating in unison!  Yet strangely, analogous policies are already on the books, and the system works so well few complain about it.

Consider: Under current U.S. law, over three hundred million people are free to move to my home town of Oakton, Virginia.  Population: About 34,000.  Thus, the population of Oakton could legally increase by a factor of almost 9000.  Under the status quo, moreover, there is no waiting period.  If everyone in the United States decides to move to Oakton today, they’re free to do so.

How come no one’s worried about the swamping of Oakton?  Part of the reason, of course, is that there’s no pent-up demand to live in Oakton.  The deeper reason, though, is that housing markets would peacefully regulate migration even if the whole country suddenly decided Oakton was an earthly paradise. 

If demand for living in Oakton suddenly spiked, the market provides a short-run and a long-run solution.  In the short-run, a demand spike leads to higher rents and housing prices, discouraging relocation without depriving anyone of the right to relocate.  In the long-run, these higher real estate prices provide an incentive for construction firms to build more housing.  As a result, housing prices would gradually decline from their temporary high – and the population of newly-popular Oakton would gradually swell. 

Over the course of a decade or two, market forces could easily transform Oakton into a metropolis a hundred times its current size.  There’s plenty of room to do so: Oakton has over 25% of the land area of Manhattan.  Is such a population growth realistic at the national level?  Yes.  If the continental U.S. had the population density of suburban Oakton, its total population would be about ten billion – more than the current population of the planet. 

True, as I’ve explained before, most people on earth don’t want to immigrate anytime soon.  Due to diaspora dynamics, immigration from a country starts out low, then gradually snowballs.  It took about a century of open borders with Puerto Rico before half its people moved here.  My point, though, is that housing markets provide the necessary incentives for massive yet orderly migration.  These markets already quietly guide internal migration.  They are quite able to do the same for external migration.  Let them come, and we will build it – for the market price.