When homelessness increased nationwide in the early 1980s, California cities responded with ever more laws that unfairly punished the poor and failed to improve the problem, according to a critical UC Berkeley report released Thursday.

Over the past 30 years, cities statewide “have been engaged in a race to the bottom by increasing criminalization, hoping to drive homeless people away and make them someone else’s problem,” the study says.

The 53-page report, authored by the UC Berkeley School of Law Policy Advocacy Clinic, says the rising number of anti-homeless laws has been costly for taxpayers and brought more hardship than help to the state’s most vulnerable residents.

The findings will help the public better understand how cities treat the homeless, said Paul Boden, head of the Western Regional Advocacy Project, which works to eliminate root causes of civil and human rights abuses suffered by the poor and homeless.

“It confirms our own street outreach surveys of hundreds of homeless people, who are increasingly harassed and punished for their mere presence in public,” Boden said, “It’s all too reminiscent of Jim Crow … and (other past) ugly laws that targeted marginalized groups.”

The report was written by more than 20 contributors from statewide social services agencies, police departments and think tanks. It used arrest data compiled by the FBI, the state Department of Justice and detailed case studies in San Francisco, Sacramento and San Diego.

By studying homeless laws set by 58 California cities — where 75 percent of the state’s homeless live — it found that those municipalities have enacted at least 500 laws restricting four activities associated with homeless people:

Standing or sitting in public places;

Sleeping or camping in vehicles and other public places;

Begging and panhandling; and