Delegates protesting the Trans-Pacific Partnership hold up signs at the Democratic National Convention in Philadelphia last month. (Carlos Barria/Reuters)

Americans are hard to pin down when it comes to international trade. In surveys, participants give wildly different answers when asked about the issue, depending on how pollsters phrase their questions. On the one hand, 58 percent of Americans say that international trade is more of an opportunity than a threat, according to Gallup. Yet 2 in 3 say there should be more restrictions on imported goods, a Bloomberg poll found.

A new academic paper could help explain some of these contradictions. The study, which will be published in the journal International Organization, suggests that Americans will support international commerce, but only as long as it benefits the United States. A draft of the study was released online Thursday.

Many economists argue that trade enriches both the United States and foreign countries, but only about 1 in 9 Americans see it that way, the study found. They support trade in theory, but their experience — closed factories, reduced wages — makes them skeptical of the broader benefits for the country.

This helps explain why the nation is so intensely divided on the Trans-Pacific Partnership, the trade deal the Obama administration has negotiated with 11 other Pacific countries. If ratified, the agreement would establish shared standards for labor, intellectual property and the environment. It would also reduce tariffs on goods shipped among the member countries.

Economists say the TPP would benefit the United States, but much less so than other member countries such as Vietnam and Malaysia.

America first

The authors of the new study, Diana Mutz and Eunji Kim of the University of Pennsylvania, conducted an online survey with a nationally representative sample of Americans. They described a hypothetical trade policy and gave the participants in the survey different explanations of the likely consequences for employment.

Some were told, for example, that 10 foreigners would get a job for every American worker who lost one. Others were told that 100 Americans would gain employment for every foreigner who lost a job. Some were told that the policy would employ more people both abroad and in the United States, and others were told that people would lose their jobs all around.

The researchers created several versions of each scenario with different figures for the gains and losses in employment. This array of questions allowed the researchers to examine Americans' views on trade in a systematic way.

The results were striking. Participants in the survey showed little concern for foreign workers if their well-being came at the expense of even one American’s. Even among participants who were told that for every American who was put out of work because of the new policy, 1,000 foreigners would gain jobs overseas, 78 percent said they would oppose the policy.

Most economists contend that while trade might result in disemployment and reduced wages for workers in specific U.S. industries, international commerce benefits the United States on the whole, as it does foreign countries. Yet this optimistic view of trade is rare among the general public, Mutz and Kim found.

Just 11 percent agreed that international trade in general yields gains for both the United States and foreign countries. Fifty percent said that trade helped other countries while putting the United States at a disadvantage. Thirty percent said that trade had no effect either way.

“Overwhelmingly, Americans are scapegoating other countries and blaming them for job loss,” Mutz said.

If economists could persuade the public to see things their way, Americans’ cool attitude toward trade would be very different. Among those participants in Mutz and Kim’s study who were told that the hypothetical new policy would benefit both sides of the deal, 68 percent supported it.

Taking care of our own

As part of the survey, participants had an opportunity to write freely about how they felt about the experiment. Some offered compelling explanations for their choice to favor Americans over foreigners.

“Although I sympathize with all people, I was thinking we need to take care of our own first, because that is most natural,” one participant wrote.

“Our domestic policy in the United States of America should be take care of our own first, PERIOD!” wrote another. “When there is no longer a line at the unemployment office or people living in homeless shelters or children going to be hungry then Americans should consider a trade policy that benefits those that live outside our country.”

Conservative columnists Ross Douthat and Reihan Salam offered an intellectual defense of this point of view in the New York Times last month. “As Americans we are — or ought to be — linked by bonds of affection and a sense of shared fate,” they wrote.

Michael Norton, a psychologist at Harvard University who was not involved in the new study, was skeptical of those justifications. He noted that even when the gains to foreign countries far outweighed the losses to the United States, the vast majority of participants in Mutz and Kim’s study focused only on what the policy would mean for Americans.

That kind of decision-making is selfish, Norton suggested. “You should be sensitive to the relative costs and benefits,” he said.

Correction: This story has been updated to correct the spelling of Diana Mutz's name.