More than 80,000 people applied for unemployment insurance in Massachusetts last week, down about 22 percent compared to the week before, according to the state Executive Office of Labor and Workforce Development.

Numbers are dropping, state officials said, because many workers have already been laid off as results of the COVID-19 shutdown. Since March 15, nearly 652,000 people have filed unemployment claims and currently about 400,000 people are receiving benefits, the state said on Thursday.

To meet increasing demand, the state Department of Unemployment Assistance increased its staff to 1,000 workers from about 50 over the last month. The state also launched itsPandemic Unemployment Assistanceprogram for people who are self-employed — receiving more than 200,000 applications in the first days, state officials said.

The numbers add to a spiraling unemployment rate across the country, reaching an unprecedented 11 percent for the week ending April 11, according to seasonally adjusted data released Thursday by the U.S. Department of Labor. Some 4.4 million people filed initial claims last week, federal data shows.

Jonathan Gruber, an economics professor at the Massachusetts Institute of Technology, said there is no doubt that the country is heading into a deep recession not seen in the U.S. since the 1930s.

“The big question is, What will the recovery look like?’’ he said. “How many people will be back to work in three months, that we just don’t know.”