Donald Trump at a rally Aug. 5 in Des Moines. (Evan Vucci/AP)

Republican presidential candidate Donald Trump has stocked his economic team with wealthy financiers and billionaires, including some who have had close ties to his companies, in a move that brings a group of powerful businessmen inside his campaign but could also threaten his populist message.

The 13 outside advisers announced Friday include a banker who loaned Trump’s casinos $600 million during their bankruptcies, as well as a hedge-fund manager who famously made a fortune betting against the U.S. housing market before the financial crisis. There are no women on the list.

In selecting a team on which the typical adviser is almost certainly worth hundreds of millions of dollars, Trump reinforced his pitch to voters that having already achieved financial success is critical to understanding what needs to be done to boost the U.S. economy. In a statement, he hailed “a formidable group of experienced and talented individuals” advising him, declaring, “I am going to be the greatest jobs President our country has ever seen.”

But the team drew criticism from liberal and conservative economists who said it badly lacked the policy expertise and economic credentials that have traditionally defined past Republican and Democratic campaigns.

“The purpose of having any economist on your campaign is it allows the candidate to be schooled on the issues, so if you get questions, you can be prepared to handle them,” said Greg Mankiw, a Harvard University economist who advised GOP nominee Mitt Romney in 2012 and served as top White House economist for President George W. Bush. “Trump doesn’t seem that interested in being conversant in issues,” he added, “so maybe, from his perspective, he didn’t need that kind of help.”

Mankiw said he will not vote for Trump, citing the nominee’s policies on trade and immigration. Trump’s team includes no prominent economists from the past several GOP campaigns or senior economic officials from previous Republican administrations. There is only one academic economist in the group and only one well-known tax policy expert.

Trump long led Democratic rival Hillary Clinton in polls on the question of who would better handle the economy, but that advantage has vanished following the parties’ national conventions. He has also sought to portray the economy as weak, though that could become more difficult in light of Friday’s hiring report, which said the country added 255,000 jobs in July, higher than expectations.

Trump’s new economic team includes Harold Hamm, a self-made oil billionaire who was an energy adviser to Romney’s 2012 presidential campaign; Dan DiMicco, a former chief executive of steelmaker Nucor; Steven Mnuchin, Trump’s national finance director, who is chairman and chief executive of the hedge fund Dune Capital Management; Steve Roth, founder and chief executive of Vornado Realty Trust; hedge-fund billionaire John Paulson; Howard Lorber, chief executive of the Vector Group; real estate investor Tom Barrack; bankers Stephen M. Calk and Andy Beal; and financier Steve Feinberg.

Business ties link Trump and several of those men. It was Beal’s banks that loaned Trump $600 million during his casino bankruptcies, according to Bloomberg, and Trump once said Beal has “20/20 vision into what is going to happen in the future.” Barrack sold Trump the Plaza Hotel in New York for $410 million, shortly before the city’s hotel market cratered. Trump still called him “a totally brilliant guy.”

The only member who has a doctorate in economics is Peter Navarro of the University of California at Irvine, who focuses on trade with China and who three times ran unsuccessfully for public office in San Diego.

The leading tax expert is Stephen Moore, who founded the Club for Growth and was a longtime columnist for the Wall Street Journal. There is also a former U.S. Senate candidate, David Malpass, who served in the Reagan and George H.W. Bush administrations and who now runs an economic consulting firm.

On the campaign staff level, the team is led by policy director Stephen Miller, a former aide to Sen. Jeff Sessions (R-Ala.), and deputy director Dan Kowalski.

Justin Wolfers, a liberal economist at the University of Michigan, said the group undermined Trump’s promise to voters that he would assemble “the best people” to staff his administration. “This is the least distinguished, least qualified economic team of any candidate in my lifetime,” Wolfers said.

“If you said that what I had to do was only formulate an economic policy team exclusively of rich white guys who had business backgrounds and were all named Steve,” Wolfers added — referencing the names of six members of group — “I still wouldn’t choose Steves only from Wall Street, real estate and mining.”

A Trump spokeswoman did not respond to a request for comment on the criticism.

Trump also takes economic advice from several people who were not listed in Friday’s release, including Arthur Laffer, the former Reagan administration economist who is known as the god­father of supply-side economics; Larry Kudlow, a financial commentator who is a Laffer disciple; and Trump’s children, including his daughter Ivanka.

Notably missing from the official list is Carl Icahn, the famed activist investor whom Trump frequently praises on the campaign trail. There are also no researchers who focus on middle-class or family issues specifically, an area Trump aides have suggested they will highlight.

“Issues facing the middle class and working women are especially important this election cycle,” said Abby McCloskey, an economist who was policy director for former Texas governor Rick Perry’s short-lived campaign for the Republican presidential nomination. “Trump could have signaled his commitment to these issues by publicly surrounding himself with people who have expertise on these topics. He chose not to.”

Trump’s pitch has long been that the most successful members of the business world know what it takes to save the middle class. The advisers reinforce that idea.

Lorber, for example, earned $42.5 million in 2015, and his compensation package, according to the Real Deal, a real estate news site, included the use of a company car and driver, club memberships, corporate plane use and a $90,000 allowance for lodging and expenses.

Voters at Trump rallies frequently cite business success as evidence that Trump could improve their individual fortunes.

Patty Adams said last week before a Trump rally in Colorado Springs that she has been supporting Trump since he first announced his candidacy last summer, in large part because of his business record. She said that, particularly with two children in college, she is worried about the country’s economic future.

“We need jobs. We need people off the entitlement dole. I’ve never seen so many homeless and street people. Obama has had eight years to fix it, and he hasn’t,” Adams said, adding, “He’s a businessman, and I think we need a different direction.”

Democrats warned Friday that Trump’s investor-heavy crew could muddle his attempt to appeal to Wall Street and paint Clinton as the candidate of Wall Street.

“He does sell himself as a billionaire and someone who knows all the tricks of the trade,” said Jared Bernstein, a former top economic adviser to Vice President Biden who now advises Clinton on policy. “So aligning himself with similar billionaires may be okay in his case. But you couldn’t find a group further away from the people he’s trying to woo.”

Like Trump’s, Clinton’s inner circle also includes some longtime associates, such as Neera Tanden and Gene Sperling. But she also has spent two years reaching out to more than 200 experts, some of whom she had never met before, to build a sprawling economic agenda.

The contrast is clear in their policy proposals thus far. Trump’s are few, and they focus on a few recurring themes. Clinton’s are many, and detailed.

Jose A. DelReal in Colorado Springs contributed to this report.