Some applications are missing information. New York analyzed a million claims and found many had been delayed because of a missing employer identification number. In such cases, each applicant has to be called back. Callers looking for updates also flood the system, increasing the wait for those who need to correct a mistake.

The seasonally adjusted number of people filing initial unemployment claims is down from late March and early April, when more than six million people applied for benefits two weeks in a row. But that’s a small consolation in light of the larger economic picture, economists said. Before the pandemic, just over 200,000 people a week applied for new unemployment benefits.

“It is declining, but the level is still breathtakingly high,” said Ian Shepherdson, chief economist at Pantheon Macroeconomics. “Claims could stay in the millions for several more weeks, which is almost unfathomable.”

Mr. Shepherdson said job cuts now extended far beyond the industries initially hit by the pandemic and the ensuing lockdown in most states, like leisure and hospitality.

“You can’t close a bar twice,” he said. “Layoffs are now working their way through management and supply chains and business services.”

Millions who have managed to keep their jobs face salary cuts or furloughs, a sign of employers’ uncertainty. Given the trillions spent, “we would have hoped that federal efforts would have been more effective at stemming job losses,” said Michael Gapen, chief U.S. economist at Barclays.

Mr. Gapen said he expected the unemployment rate to hit 19.5 percent in April, a level unseen since the Depression.