Trade wars are bad but President Donald Trump’s steel and aluminum tariffs won’t have much direct impact on the U.S. economy unless the situation escalates, according to a new survey conducted by Bloomberg News.

Roughly two-thirds of the 35 economists polled by Bloomberg expect the tariffs that Trump signed last week would cause a small decrease in jobs and a small drop in U.S. economic growth, which is enjoying its third-longest expansion on record. One economist predicted a small gain in jobs. No one thought there would be a large impact in either direction.

“By themselves, the tariffs on steel and aluminum will likely have a modest impact on growth and inflation,” said Scott Brown, chief economist at Raymond James Financial in St. Petersburg, Fla. “The bigger concerns are retaliatory tariffs against U.S. exports, the possibility of a broader trade war, higher costs and greater uncertainty for global business investment.”

Trump on March 8 slapped tariffs of 25% on imported steel and 10% on aluminum, but immediately excluded Canada and Mexico -- so long as they reach a new North American Free Trade agreement that passes muster -- and said other nations could petition for an exclusion. That’s set off a race for U.S. allies to plead for special treatment, while China has warned of “strong” measures to protect its interests.

Morgan Stanley estimated the impact of the tariffs as no more than 0.3 percentage point of U.S. gross domestic product, writing in a report that they were “unlikely to derail the global macro outlook.” Barclays Plc has estimated as much as a 0.2 percentage point impact.

Trump has also tweeted a trade war is easily winnable. Most economists see losses to all sides.

'Genuinely Stupid'

“These tariffs are a really bad idea,” said James Smith, chief economist at Parsec Financial Management Inc. in Asheville, N.C. “It will cost consumers millions of dollars for each job saved in aluminum or steel production -- a genuinely stupid and counterproductive policy.”

When President George W. Bush raised steel tariffs in 2002, U.S. gross domestic product declined by $30.4 million, according to the U.S. International Trade Commission. The U.S. lost about 200,000 jobs, about 13,000 of which were in raw steel-making, by one estimate.

Eighty percent of the economists predicted a small increase in inflation from the trade policy, while the remainder saw no effect.

While there will be initially “higher import prices and substitution toward higher domestic prices,” that will be followed by disinflationary effects when tariffs diminish demand, said Derek Holt, an economist at Scotiabank in Toronto.

More problematic than the U.S. tariffs is the likelihood that other countries will respond in kind. The European Union has threatened targeted retaliation on iconic U.S. brands, including Harley-Davidson Inc. motorcycles, Levi Strauss & Co. jeans and bourbon whiskey, if the bloc fails to win an exemption.

“We expect the impact on U.S. growth and inflation to be fairly limited,” said Mikael Olai Milhoj, a senior analyst at Danske Bank in Copenhagen. “There is a risk that we are too optimistic and that there will be a bigger trade war, which would be negative for the global economy.”

A full-blown trade war could cost the global economy $470 billion, an analysis by Bloomberg Economics found. The profession generally views trade as helpful to both partners and the history or tit-for-tat trade tariffs as a good reason to avoid making the same mistake again.

What happens to global growth if there’s a trade war? Based on Bloomberg Economics’ estimates, if the U.S. raises import costs by 10% and the rest of the world retaliates, raising tariffs on U.S. exports, the cost by 2020 would be 0.5% of global GDP. To put that into perspective, that’s about $470 billion -- roughly the size of Thailand’s output, according to Jamie Murray and Tom Orlik, Bloomberg Economics.

The Smoot-Hawley Act, which raised U.S. tariffs on thousands of imported goods when it was passed by Congress in 1930, is often blamed for deepening the Great Depression. Yet most trade spats end up without that kind of damage, and most in the survey were hopeful.

The U.S. economy, boosted by a $1.5 trillion tax cut that Trump signed last year, is on a solid footing and the unemployment rate of 4.1% is the lowest since 2000.

“The negative impact of the tariffs -- which are a tax hike on consumers and users of steel and aluminum -- is more than offset by the benefits of the more sweeping tax reform,” said Brian Wesbury at First Trust Advisors in Wheaton, Ill. “So, the economy is set to accelerate and no one will be able to tell how much more it could have grown without the tariffs.”