The Bay Area has become more racially segregated since 1990, mirroring a long-running national trend of cities and neighborhoods dividing more starkly along ethnic lines, according to a new study by UC Berkeley researchers.

Oakland, Fremont, San Francisco and San Jose are all among cities ranked as “highly segregated” by the university’s Othering & Belonging Institute.

Although the Bay Area has one of the country’s most diverse populations, researchers say ethnic groups have settled into homogenous neighborhoods, often hindering economic advancement in segregated communities of color. But the Bay Area is not alone — more than 8 in 10 metro areas have become more exclusionary in recent decades.

“The United States continues to be a place of segregation, not integration,” said report author Stephen Menendian. The study measured and ranked demographic, housing and income patterns in nearly 200 U.S. metros with populations greater than 200,000.

Menendian said land use policies, including restrictions on denser housing and apartments, have driven segregation, particularly in the Bay Area. “It’s crystal clear that excessive restrictive zoning plays a significant role.”

Researchers believe the analysis will give elected leaders and planners another tool to gauge housing disparities and re-evaluate public policy on economic equity, policing and systemic racial biases.

The growing segregation has become a focus for regional leaders and business groups.

Ahmad Thomas, CEO of the Silicon Valley Leadership Group, said heightened awareness of racial disparities has given momentum to social, political and economic change, adding that diverse leadership benefits a business’ bottom line. Thomas has launched a SVLG initiative to increase representation of women and communities of color in leadership roles at Silicon Valley companies. “This is a core business competitive issue,” he said.

Silicon Valley tech companies have helped address inequality through innovation, and by supporting more affordable housing through policies and funding, Thomas said. “These issues are deep, systemic issues,” he said. “But I don’t view them as an intractable problem.”

The impact of segregation, Berkeley researchers say, is clear: residents in communities of color have lower future economic gains, educational achievement and poorer health.

Researchers used census data to track migration patterns, housing costs, income, education, and health metrics for every census tract in the U.S. They also incorporated exclusionary zoning maps from the 1930s, which barred people from communities of color from buying into many neighborhoods. An online map tracks segregation measures from 1980 to 2019.

For example, poverty rates are highest in segregated communities of color (21%), and about triple the rate of poverty in segregated White neighborhoods, according to the research. Black and Latino children raised in integrated neighborhoods earn about $1,000 a year more as adults than those raised in segregated communities. The income boost is even greater for Black and Latino children raised in White neighborhoods.

Moreover, the report says, “household incomes and home values in White neighborhoods are nearly twice as high as those in segregated communities of color” in the U.S. Menendian said the root cause of social and economic inequality is “racial residential segregation.”

The Bay Area was more integrated in previous generations. In 1980, neighborhoods in Santa Clara, Mountain View, San Jose, Hayward,  Milpitas, Oakland and San Francisco were considered fully integrated, researchers said. By 2019, many of those neighborhoods became more homogeneous and considered lightly segregated. Most lightly segregated Bay Area neighborhoods have become highly segregated today, researchers say.

Researchers ranked Detroit  as the most segregated city in the U.S., followed by Hialeah, Florida, a suburb of Miami with one of the highest percentages of Latino residents in the country, and Newark, N.J. Other cities in the top 10 include Chicago, Milwaukee, Cleveland, Miami, Birmingham, Ala., and New York.

In the Bay Area, Oakland ranked 14th in the U.S. by the researcher’s measure of segregation, followed by Fremont (34), San Jose (61), San Francisco (65), and Stockton (86).

The study builds off the researchers’ previous work on housing policy and analysis of zoning in the Bay Area. They found roughly 80% of the region’s residential property is zoned for single family homes — a telling indicator for racial segregation. Neighborhoods restricted to single family homes are more likely to be exclusively White than communities with a mix of apartments and homes, researchers found.