The Bay Area was more racially segregated in 2010 than it was 40 years prior, a UC Berkeley paper published Tuesday found.

Segregation in the Bay Area persisted and, in some cases, grew since 1970. Seven of the region’s nine counties had more segregation in 2010 than they did in 1970. The only two that saw declines — San Francisco and Alameda counties — remain classified as “high” segregation places.

Meanwhile, Marin, Santa Clara, Sonoma and Napa counties had relatively large increases in segregation.

That’s according to a brief from researchers at UC Berkeley’s Haas Institute for a Fair and Inclusive Society — the third in a five-part series.

But the story of where people live in relation to each other isn’t uniform across racial groups. While black residents became less segregated from white and Latino peers, for instance, Asians and Latinos both became more segregated from whites.

Black-white segregation remains the highest, even though it’s on the decline, said authors Stephen Menendian and Samir Gambhir.

One of the measures the authors used to gauge segregation is the “dissimilarity index,” which indicates the proportion of people in a racial group who would have to move for an area to become fully integrated. A score of 0 means an area is fully integrated.

The United States scored a 59 in the black-white dissimilarity index, meaning that 59 percent of white or black people across the country would have to move to reach full integration, according to the paper, which used Census data going back to 1970.

In the Bay Area, the largest decline in dissimilarity scores was that of Latinos and African Americans — from 71 in 1970 to 45 in 2010.

A different study from UC Berkeley researchers found that soaring housing prices have pushed low-income minorities to the outer edges of the Bay Area and beyond.

Land use, zoning and housing policies, in addition to discrimination, have stratified the region by race and class, said Menendian, the lead author.

“It’s very unlikely that we will solve racial inequality in a society or region that’s racially segregated,” he said. “Take health outcomes: They are a product of where people live.”

The paper said that while there are fewer areas comprising one race — all-white and all-black neighborhoods, for instance — “the typical member of a racial group still resides in a demographically isolated” area.

Kimberly Veklerov is a San Francisco Chronicle staff writer. Email: kveklerov@sfchronicle.com Twitter: @kveklerov