A new interactive map is putting Bay Area neighborhoods under the microscope, revealing which blocks still bring people of different incomes under the same roof and which have split into opposite extremes. Some dense city tracts turn out to be surprisingly balanced. Large stretches of suburbia and a few urban pockets, though, are almost entirely high-income or firmly low-income territory. For anyone who lives here, it is a quick reality check on whether your corner of the region is economically mixed or stuck at one end of the income ladder.
As reported by the San Francisco Chronicle, reporters Aseem Shukla and Harsha Devulapalli crunched income counts for about 1,800 Bay Area census tracts. They used a statistical tool called Shannon entropy to score how evenly households in each tract are spread across five income buckets. Drawing on the Census Bureau’s 2020-2024 five-year American Community Survey estimates, the Chronicle notes that households making 200,000 dollars or more now represent about a third of all households in the region. The interactive lets readers see every tract ranked from least to most mixed and compare their own neighborhood with the rest of the Bay Area.
How the ranking works
The ranking leans on the American Community Survey’s tract-level income table B19001, which lays out the detailed income counts the Chronicle used, according to the U.S. Census Bureau. The Census table normally breaks incomes into 19 narrow brackets. For this project, the Chronicle collapsed those brackets into five broader ranges so that Shannon entropy better captures the Bay Area’s outsized share of very high earners. To avoid odd swings in tiny areas, the paper limited its map to tracts with at least 500 households before assigning each one a mixing score.
Where incomes actually mix
Some of the most economically mixed places on the new map are exactly where you might expect a jumble of people and paychecks: dense, urban neighborhoods. In Oakland, Adams Point ranks as the East Bay’s most income-mixed census tract. In San Francisco, a tract in the Portola comes out on top. In the South Bay, a tract that includes Turtle Rock Park in south San Jose leads the pack. The Chronicle also highlights a tract in Sonoma Valley where trailers and mansions share the same statistical footprint, a reminder that mixing can look very different from one community to the next.
Urban scholar George Galster, quoted in the Chronicle’s coverage, cautions that the underlying story can be more complicated than a single score. A tract that looks well mixed today might simply be in the churn of gentrification, while others stay stably diverse because they have a genuinely varied housing stock. As he puts it, the key question is, “Is a place stably mixed or temporarily mixed?” Those snapshots, along with the regionwide rankings, play out in the Chronicle’s full interactive project, according to the San Francisco Chronicle.
Why mixing matters
Researchers have found that growing up or living in mixed or higher-opportunity neighborhoods can translate into concrete gains for low-income residents, including higher earnings and better school outcomes for children who spend their formative years in those areas. A Brookings commentary has framed a careful, policy-minded version of gentrification as one way to chip away at concentrated poverty, while City Observatory summarizes research showing measurable benefits for public-housing residents in rising-income neighborhoods. Long-term academic work has tied durable income diversity most often to a mix of housing types rather than a single, one-off redevelopment wave, a pattern that urban research has documented. Cities research backs the idea that a variety of housing options helps keep that mix intact over time.
What the map means locally
For Bay Area officials, planners, and community advocates, seeing where incomes cluster or mix at the census-tract level can sharpen where to focus policy tools. Areas that still have a range of incomes may need stronger tenant protections, targeted preservation of existing affordable housing, or new missing-middle construction to keep that balance from tipping. Regional tools and dashboards from the Bay Area Equity Atlas show similar patterns of concentrated advantage and disadvantage to those seen in the Chronicle’s project. Together, they point to paired policy responses, such as stronger renter protections, more strategic preservation funding, and inclusionary housing rules that aim to stabilize mixed neighborhoods rather than let them slide toward one extreme…