Thanks to Burbed reader Real Estater for nominating this article by posting it in the comments on Friday.
Image from USA Today
By Eric Kurhi and Matt O’Brien, Contra Costa Times
Posted: 03/18/2011 03:20:18 PM PDT
HAYWARD — Close to the geographic center of a city known as the “Heart of the Bay,” Luciano Ruiz peered out the pickup window of a burger joint in what is, by one measure, the most racially diverse neighborhood in California.
“There’s been a mix of people here ever since I grew up,” said Ruiz, 18. “It’s always been mainly Latino down here in South Hayward, but now you see more African-Americans, a lot more Asians. I’ve seen a little increase in Middle Eastern people.”
The 2010 census shows a collection of census tracts in the Hayward flatlands as the most diverse in California and a microcosm of the state’s likely future. Latinos are the largest group, but share the space with many other people. Multicultural churches, mosques and businesses are in walking distance.
Thirty-five miles away, in the Walnut Creek retirement community of Rossmoor, a cluster of census tracts reflect an older, less integrated California. About 90 percent of residents are white and less than 1 percent are African-American in the Bay Area’s least-diverse neighborhood.
“It’s probably accurate,” said Rossmoor resident David Smith of the newly released statistics. “Our population is overwhelmingly white.”
Since this is from the Contra Costa Times, there’s little about neighborhoods in Santa Clara or San Mateo County, and which would be the most or least diverse. East Palo Alto was specifically called out as one of the 10 most diverse communities in California. The diversity index is the probability that two randomly picked people from the area would be of different race or ethnicity. Maybe you might have an idea which neighborhoods you’d nominate?
Anyway, I looked up the data, and East Palo Alto has a DI of 83.4 (the highest was 86.4 and Hayward was 85.1). Oakland was 81.1. Not mentioned in the article are Sacramento, 79.6, South San Francisco, 79.0, San Jose, 77.1, San Bruno, 76.3, Santa Clara, 
71.8, and Sunnyvale, 70.7. On the other end of the scale we find Belvedere, 16.4, Portola Valley, 22.3, Woodside, 25.2, and Boulder Creek at 26. Don’t assume that a low DI means white-bread; the Central Valley’s Mendota is 96.6% Hispanic and has a DI of 26.0.
In case you’re wondering how some areas end up with lots of diversity, here’s the secret, according to the above article:
It didn’t happen overnight,” Bogue said. “Just like anywhere, somebody puts a house up for sale, somebody looks at it and somebody buys it.”
Yeah, that couldn’t happen in Atherton, where houses are bequeathed. But while houses are occasionally listed for sale in homogenous census tracts, the diverse ones, such as Richmond, San Pablo, Pittsburg, Hayward, Vallejo, Oakland and San Leandro have another interesting thing in common.
Local historian Frank Goulart said affordability has also long attracted a broad spectrum of people to parts of Hayward.
“If you want an honest answer, it’s the cheap housing,” Goulart said.
He said many of the homes in the city’s most diverse tracts “were built like shacks.”
There you go. Diversity is code for crapboxes (like this one above, in Hayward, the City of Diversity). But don’t worry about it. The majority of California public school students are now Hispanic, so the Diversity Index must be heading down (see Mendota, above). That means housing quality will go up, so the Real Bay Area will get bigger!
There’s no danger of that in Silicon Valley, though. Santa Clara County’s index is a kumbayah 74, almost as multicultural as Alameda County’s state-topping 78. The least diverse Bay Area County? Marin, at 45. The overall state index is 72.9, second only to Hawaii’s 81.1.
But what’s more important is housing! And the county with the highest percentage of vacant housing units goes to Alpine, with a whopping 71% of its housing sitting empty. For the Bay Area, the winner is Sonoma, with 9.2%, 
but Santa Cruz’s 9.7% would have beaten it had any of the county physically come into contact with the Bay. Meanwhile San Mateo and Santa Clara county are both in the 4’s, while San Francisco managed double: 8.3% of the housing units sitting empty.
There’s stats, stats, stats to play with, so have fun courtesy of USA Today. Data is available by city as well, so go wild and wonder why the city (town?) of Almanor has 100% of their 75 housing units empty.
Photo above: foreclosed home in Hayward, showcasing diversity.
