WASHINGTON — U.S. hiring slowed to a near-standstill in May, sowing doubts about the economy’s health and complicating the Federal Reserve’s efforts to raise interest rates.

While unemployment slid from 5 percent to 4.7 percent, the lowest since November 2007, the rate fell for a troubling reason: Nearly a half-million jobless Americans stopped looking for work and so were no longer counted as unemployed.

Employers added just 38,000 jobs in May, the fewest in over five years.

Less-educated workers bore the brunt of the hiring slump, with a quarter-million high school dropouts losing their jobs in May. That has perpetuated a long-term trend toward a two-tiered job market, with college-educated adults more likely to be employed and earning steady raises.

“The shockingly low payrolls gain in May provides further evidence that the economy is showing clear signs of slowing,” said Laura Rosner, an economist at BNP Paribas.

The much-weaker-than-expected figure raised doubts that the Federal Reserve will increase short-term interest rates at its next meeting in mid-June or perhaps even at its subsequent meeting in July. Many analysts had expected an increase by July.

On Wall Street, the Dow Jones industrial average closed down 32 points, for a loss of 0.2 percent.

The disappointing report spilled into the presidential race, with Donald Trump referring to it on Twitter as a “terrible jobs report” and a “bombshell.” The figures come just days after President Barack Obama touted his economic record in Elkhart, Ind.

Americans particularly worried about the economy have been more likely to support outsider candidates such as Trump and Sen. Bernie Sanders.

Trump’s support has also come disproportionately from adults without college degrees, and Friday’s report served as a stark reminder that less-educated Americans have continued to lose economic ground even as overall hiring and growth have picked up since the Great Recession.

Essentially all of the 7 million jobs added over the past decade belong to workers with at least some college experience. The number of high school graduates with jobs is 3 million lower than 10 years ago.

“The high school jobs are gone and they’re not coming back,” said Anthony Carnevale, director of the Georgetown University Center on Education and Workforce. “It’s driven by a fundamental shift from an industrial economy to a post-industrial economy.”

Job gains in March and April were also revised downward on Friday, leaving average monthly hiring at a pace of just 116,000 in the past three months.