The Optimal Number of Immigrants

John Cochrane:

The optimal number of immigrants: Hoover's Peregrine asked me to write an essay with the title, "What is the optimal number of immigrants to the U.S?"  (Original version and prettier formatting here. Also a related podcast here.) My answer: Two billion, two million, fifty-two thousand and thirty-five (2,002,052,035). Seriously.

The United States is made up of three and a half million square miles, with 84 people per square mile. The United Kingdom has 650 people per square mile. If we let in two billion people, we’ll have no more population density than the UK.

Why the UK? Well, it seems really pretty country and none too crowded on “Masterpiece Theater.” The Netherlands is also attractive with 1,250 people per square mile, so maybe four billion. Okay, maybe more of the US is uninhabitable desert or tundra, so maybe only one billion. However you cut it, the US still looks severely underpopulated relative to many other pleasant advanced countries.

As you can see by my playful calculation, the title of this essay asks the wrong question. ...