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The number of open jobs in the U.S. remains near a record high, helping to keep unemployment low.

The numbers: The number of laid-off workers who applied for unemployment benefits declined in mid-March to a one-month low, suggesting little deterioration in a robust labor market that’s powered the economy over the past several years.

Initial jobless claims, a rough measure of layoffs, fell by 9,000 to 221,000 in the seven days ended March 16, the government said Thursday. Economists surveyed by MarketWatch had forecast claims to total 225,000.

The more stable monthly average of claims rose by 1,000 to 225,000.

The number of people already collecting unemployment benefits, known as continuing claims, fell by 27,000 to 1.7 million.

What happened: Jobless claims sank below the key threshold of 300,000 in 2015 and have stayed low ever since, but they are no longer falling.

The four-week average, for example, bottomed out at a 49-year low of 206,000 last September. It’s drifted up over the past several months to as high as 236,000 in mid-February before settling back down.

Claims are viewed as a sort of modern canary in the coal mine. They tend to give the earliest clues of whether the economy is getting better or worse.

Big picture: The U.S. labor market is still extremely strong even though the economy has slowed. The unemployment rate dipped to 3.8% last month, layoffs are ultra-low and job opening remain near a record high.

So long as most Americans are working, earning paychecks and spending the economy should be OK, economists say.

Market reaction: The Dow Jones Industrial Average

DJIA, +0.13%

and Standard & Poor’s

SPX, +0.14%

were set to open lower in Thursday trades.

The 10-year Treasury yield

TMUBMUSD10Y, -0.18%

 fell several basis points to 2.51%, reflecting a softer economy and the Federal Reserve’s decision to stop raising interest rates. Just five months ago, the yield hit a seven-year peak of 3.23%.