Thomas Donlan of Barron’s uses his latest editorial commentary to spell out key elements of the Trans-Pacific Partnership trade deal.

Although TPP is considerably less than a free-trade agreement, it does aim to reduce tariffs and regulatory barriers to trade among the signatories—especially the poorest countries that have the largest and broadest trade restrictions and taxes. For example, the Peterson Institute for International Economics estimated that Vietnam could gain $41 billion a year of new business revenue by 2030, which would be an annual gain of 8% over its annual GDP in 2015.

The U.S., on the other hand, has fewer trade restrictions and will keep more of its important ones for years to come. It will not reduce trade barriers on autos for 25 years. It will keep its sugar protection with only minor changes, and it joined Canada in refusing to make a deal on dairy products. The U.S. also won’t change prohibitions on foreign companies to compete in domestic air transport or ocean shipping between U.S. ports.

The Peterson Institute estimates annual U.S. gains by 2030 will be $131 billion a year, or 0.5% of 2015 GDP, but it could have been a lot more if the U.S. could have seen its way clear to taking the advice it hands out so generously to other countries.

U.S. gains from TPP clearly will not come from increased imports lowering the price of goods for consumers. More benefits will occur through increased opportunities for direct investment in and exporting to foreign countries. The most important sector will be services, which are hard to measure when providers and customers bundle them with products and make deals across borders and oceans.

Adam Posen, president of the Peterson Institute, says the main gains for the U.S. will come in an entirely different way.

“More and more, we recognize that important gains from free trade come from productivity growth by reallocating capital and labor,” says Posen. Such benefits would include increased specialization, greater economies of scale, and improved consumer choice, according to Robert Z. Lawrence of Harvard University in a Peterson blog post.

They said it nicely, but they were saying that trade creates winners and losers throughout the economy and that, in the U.S., winners will outnumber losers in jobs and income. That doesn’t mean there are no losers; it means we would be wrong to worry about them so much that we give up the national income—and wages—that will be earned by winners.