If barriers to immigration are orders of magnitude steeper than barriers to trade, removing such obstacles — allowing workers to flock
to where they are most productive — would provide a much bigger impetus to the economy than any effort at trade liberalization.
George Borjas of Harvard, by no means a supporter of liberal immigration, has estimated
that the newcomers who arrived in the United States from 1990 to 2010 reduced the wages of American-born high school dropouts over the long term by 3.1 percent — or some $900 a year.
But as he barrels ahead with his promise to restrict immigration — barring people from some Muslim-majority countries, limiting work visas,
expelling millions who are here illegally — the president might want to ponder how this fits the theme of making America “great again.”
For his plan, at the scale he promises, would shrink the American economy and impoverish the world.
“If trade deals were strictly about efficiency and growing the size of the overall economic pie,” argues Dani Rodrik of the Kennedy School, “trade negotiators would drop everything else on their agenda
and spend their whole time trying to strike a bargain whereby workers from poor countries could participate in the labor markets of the rich countries.”
Indeed, some economists have estimated that allowing free cross-border movement of labor could more than double the world’s gross domestic product.