The rebuilding of fire-damaged structures in the North Coast would take over 6,000 construction workers three years to accomplish, an economist told business leaders Friday in Santa Rosa.

Attracting and housing so many workers will be hard, but the county’s economy won’t keep expanding without more homes, Christopher Thornberg said during an annual economic breakfast held at the Hyatt Regency Sonoma Wine Country in Railroad Square.

Making his 14th appearance at the county-sponsored breakfast, Thornberg gave an overview of the national economy that was sharply critical of both President Donald Trump and the Republican-led proposals for tax reform. He then warned civic and business leaders that the county must provide more housing for workers.

“You have to build now,” said Thornberg, a founding partner of Beacon Economics, an independent research and consulting firm in Los Angeles. “Otherwise, the economy is simply going to stop growing.”

Thornberg spoke to nearly 500 people in the aftermath here of the most destructive wildfires in U.S. history. In the county, the fires killed 23 people and destroyed 5,100 homes.

County Supervisor James Gore earlier told the audience that some burned-out residents may choose to leave the county, but “they should never go because we failed them.”

“It’s our time,” Gore said in a call to action. “Let’s not screw it up.”

Thornberg followed by reminding listeners of his previous recommendations for both the county and California to encourage more housing.

“What this fire has done is simply intensified a crisis that already existed,” he said.

The county is essentially “beyond full employment” and the challenge of finding new employees is getting worse, Thornberg said.

“You’re running out of workers because you’re running out of housing,” he said.

He showed a chart estimating that a one-year effort to rebuild the roughly $3 billion worth of burned structures in the region would require 18,839 workers. The wages for that effort would exceed $1 billion.

Spread the rebuild over three years and the region annually would require nearly 6,300 workers for the task. For perspective, in Sonoma County, where over 85 percent of the losses occurred, building companies last month employed 13,900 construction workers.

Thus, when the workers needed for a three-year rebuild are added in, the county’s total construction work force would far exceed the number employed here in more than 17 years, including at the height of a national housing bubble.

Much of the U.S. is experiencing a shortage of workers, Thornberg said, which is why he strongly opposes efforts to take existing protections away from millennial-age children of illegal immigrants.

“We need them,” he said, prompting a burst of applause from the audience.

Thornberg criticized the proposed GOP tax plans for giving big tax breaks to corporations and the top 1 percent of wealthy Americans, even as the federal deficit mushrooms and Social Security and Medicare soon will encounter ballooning costs from a tidal wave of baby boomers moving into their elder years.

“This is nuts,” he said.

You can reach Staff Writer Robert Digitale at 707-521-5285 or robert.digitale@pressdemocrat.com. On Twitter @rdigit.