Study Says Diamond Bar Remains Multiracial, Has One of the Largest Increases in Asian/Pacific Islander Population

Southern California cities are on average more racially balanced than they were 20 years ago, though some cities are starting to become less multiracial than they used to be, according to a University of Southern California study released today.

The steady decline in the share of whites and blacks in the five-county region, combined with a steady increase in the population of Hispanics and Asian and Pacific Islanders has led to more cities becoming multiracial, particularly in Orange and Riverside counties.

The total percentage of multiracial cities in Los Angeles, Orange, Riverside, San Bernardino and Ventura counties grew to 61.5 percent in 2010, up from 51.2 percent in 1990.

According to the study, Diamond Bar is a three-way city, meaning there are three significant population groups, with the smallest accounting for at least 15 percent of the total population: White, Asian, and Latino. It ranked seventh out of 25 cities in Southern California for the largest increase in Asian and Pacific Islander population.

Walnut has become less multicultural, because of changes in its Latino and Asian populations. It ranked 16th out of 17 cities for the largest decrease in the Latino population and 25th out of 25 cities for the largest decrease in Black residents.  The city ranked 12th out of 25 communities for the largest increase in the Asian/Pacific Islander population, according to the data.

The study by USC's PopDynamics Research Group in the Sol Price School of Public Policy defines a city as multiracial if its two largest race groups make up at least 20 percent of the population, if three different races make up at least 15 percent of the city, or where the fourth largest race group represents at least 8 percent of the population and the largest race group is no more than 55 percent. The latter is considered the most diverse type of city.

The report, "Racially Balanced Cities in Southern California, 1999 to 2010," used census data from 1990, 2000 and 2010.

"Los Angeles is leading the nation once again in this multiracial experience,'" said Dowell Myers, a USC professor of urban planning and demography and the study's lead author. "Right now, we're at a sweet spot for racial balance in Southern California. Decline in the white population and growth among Latinos or Asians only increases racial balance up to a point. Some cities have already started to lose their balance.''

Riverside County overtook San Bernardino County as having the highest percentage of multi-racial cities. Twenty-one of the 26 cities in Riverside County were defined as multiracial in 2010, according to the study. For the first time in recent decades, San Bernardino County had three cities with significant populations of four racial groups represented -- Highland, Loma Linda and Rancho Cucamonga.

At 53.4 percent, Los Angeles County had the lowest percentage of cities with a multiracial makeup. However, 10 of the 13 cities across the region deemed the most racially balanced were in L.A. County.

- Melanie C. Johnson and Catherine Garcia contributed to this report.