It's one of Donald Trump's favorite campaign promises.
"I will bring jobs back from China. I will bring jobs back from Japan. I will bring jobs back from Mexico," he said in last week's Republican debate. "I'm going to bring jobs back and I'll start bringing them back very fast."
That's not likely to happen, however, several economists say. Many of the jobs that moved overseas are in manufacturing, and the majority of those positions aren't coming back.
The nation has seen a decline of nearly 5.5 million manufacturing jobs over the past 25 years. Just how many of those jobs disappeared due to trade remains a matter of debate among economists. About 20 million people change jobs involuntarily due to layoffs and plant closures every year, and less than 5% of those are due to imports, said Robert Lawrence, a professor of international trade and investment at Harvard's Kennedy School of Government.
Looking specifically at China, one study found that the U.S. lost 1.5 million manufacturing jobs due to growing exports from China between 1991 and 2007. That accounts for about 20% of all manufacturing jobs shed over that period, said study co-author Gordon Hanson, an economics professor at the University of California, San Diego. (The subsequent worldwide recession prompted a slump in trade so there wasn't much of a change in between 2008 and 2011, he said.)
Trump, on his campaign website, lists four ways he would reform trade with China to keep jobs and factories in the U.S. These include declaring China a currency manipulator, ending its intellectual property violations, eliminating its illegal export subsidies and lowering the U.S. corporate tax rate to 15% to stop businesses from moving abroad. He also floated a plan to impose a 45% tariff on Chinese exports to the U.S. in a meeting with the New York Times editorial board last month.
Still, trade experts say the Republican frontrunner hasn't released detailed plans for bringing manufacturing jobs back. But even if he did, it won't be easy.
"I can't imagine anything our government could actually do to return employment in the manufacturing sector to the level it was before," said John McLaren, a University of Virginia economics professor, who has studied the impact of NAFTA and trade with Mexico on American jobs and wages.
Asked to elaborate on Trump's plans, a campaign spokeswoman replied: "There is nothing easy about making America great again, but Mr. Trump is the only one who can do it."
However, the economists CNNMoney interviewed say they doubt that. While employment in the sector may grow somewhat, the nation won't regain its status as a manufacturing center, said David Autor, an MIT economics professor who co-authored the study with Hanson.
Many of the jobs lost were in factories that made toys, clothing, furniture and other labor-intensive industries, which were relatively low-skilled. The manufacturing jobs that return will involve more technology and require more education and training, he said.
"More stuff will be made here, but it won't be by the same laid-off workers from textile and leather plants," Autor said.
Also, Americans benefit from cheaper goods made overseas. This is particularly true for poor and middle class Americans, who spend much more of their earnings on imported products, Lawrence said. Items manufactured in the United States will likely cost more.
"You'll see a huge increase in the cost of living for Americans," he said.