Is Donald Trump right about free trade costing American jobs? The answer is no, for the most part, this article from the Wall Street Journal indicates. As reporters Bob Davis and Jon Hilsenrath write, "When import booms from Japan, Mexico and Asian 'tiger' economies such as Taiwan arrived in the U.S., many cities and towns were able to adapt."

But China has been different, as the respected M.I.T. economist David Autor has concluded. "No other country," Davis and Hilsenrath write, "came close to its combination of a vast working-age population, super-low wages, government support, cheap currency and productivity gains." It's a conclusion that supports Trump's argument that opening up the U.S. to trade with China, supported by both the Clinton and Bush administrations, was a mistake, or at least was overdone.

It doesn't necessarily follow, however, that future free trade agreements would have similar effects, or that our current arrangements with China need to be changed. China's "combination" is already changing: Its working-age population isn't growing much and is even due to contract; its wages are no longer super-low and its currency is not as undervalued as it was. The next largest countries after the U.S., Indonesia and Brazil, have only 4 percent and 3 percent of world population, and neither has wages as low as China's were in 2000.

Here, as on immigration, Trump is addressing problems that are now in the past and will not likely recur. No other nation is going to disrupt the world or American economy as China did from 2000 to 2009. No other nation is going to provide the huge flow of low-skill immigrants that Mexico did from 1982 to 2007. There is more to Trump's critique than some of us (including me) have been willing to concede. But they provide less useful guidance for future policies than the candidate seems to think.