WASHINGTON – Federal Reserve Chairman Ben Bernanke on Friday gave an endorsement to one side in a debate among economists about what is the main reason unemployment is so high.

Bernanke agreed with those who see the problem being more tied to a weak economy, and less so to workers lacking the necessary skills for jobs that are available. That assessment is a big reason why the Fed is widely expected to take more steps soon to stimulate economic growth.

The “bulk of the increase in unemployment is attributable to the sharp contraction in economy activity, rather than to structural factors,” Bernanke said during a speech in Boston on Friday.

It’s an important debate because its implications affect most Americans.

The Federal Reserve can take action to boost a weak economy and bring down unemployment. But if the problems are more associated with mismatched skills, or other so-called “structural reasons,” then there’s less policymakers can do.

But lowering interest rates won’t help unemployed factory workers find jobs in an industry they may not be qualified for, such as those in the health care field.

Bernanke “weighed in forcefully on one side,” said Dana Saporta, an economist at Credit Suisse. “He’s almost assuming responsibility in a larger sense for making things better.”

Not all Fed policymakers agree with Bernanke’s assessment. Narayana Kocherlakota, president of the Federal Reserve Bank of Minneapolis, pointed out in a speech in August that job openings have increased steadily in the past year, but the unemployment rate hasn’t come down. It is currently at 9.6 percent.

Kocherlakota said a mismatch between the unemployed and the available jobs is likely the main reason.

“Firms have jobs, but can’t find appropriate workers,” he said. “The workers want to work, but can’t find appropriate jobs.”

That mismatch could be because workers aren’t qualified or because they live in areas with high unemployment and can’t move to where the jobs are. Many Americans owe more on their mortgages than their homes are worth, making it difficult to sell and move.