The decennial census plays an essential role in American democracy. Our series of blog posts examines what’s at stake for California and the challenges facing the 2020 Census, including communities that are at risk of being undercounted.

PPIC’s interactive census maps are an important tool for Californians working to ensure an accurate census count. Using estimates from the Census Bureau and the Federal Communications Commission, they highlight hard-to-count communities across the state and pinpoint reasons why certain areas may be hard to reach.

Home to about 20% of the state’s population—some 8 million people—the Bay Area has clusters of hard-to-reach places throughout the region. Of the 10 counties bordering the San Francisco, San Pablo, and Suisun Bays, including neighboring Santa Cruz County, Alameda has the highest share of very hard-to-count areas (14% of census tracts) and Napa the lowest (3%). Households in these very hard-to-count areas are less likely to respond initially to census forms and are therefore at risk of being undercounted, according to Census Bureau estimates that draw on historical trends and local demographic characteristics (e.g., race/ethnicity, age, citizenship, and housing conditions). Compared to some of California’s central and southern counties, the Bay Area has lower shares of very hard-to-count places, but there are still several areas of concern.

Some highlights:

East Bay legislative districts have the highest concentrations of very hard-to-count neighborhoods in the region. In three East Bay legislative districts, 20% or more of census tracts are considered very hard to count: Congressional District 13 (Lee), State Senate District 9 (Skinner), and State Assembly District 18 (Bonta). Each of these districts represents Oakland and other parts of the East Bay.
But there are hard-to-reach neighborhoods throughout the Bay Area. In addition to Oakland, residents in the East Bay cities of Richmond, Berkeley, and Hayward are likely to be hard to reach, with around 30% of households in many neighborhoods predicted not to respond initially to the census. In San Francisco, particularly hard-to-reach neighborhoods include SoMa, the Mission District, and Bayview/Hunters Point. Other cities with many hard-to-count census tracts include Santa Cruz, San Jose, East Palo Alto, and Redwood City on the Peninsula, and Antioch, Santa Rosa, and Vallejo in the North Bay. It is important to keep in mind that communities may be hard to count for multiple reasons.
Understanding local population trends can help guide effective outreach. Compared to the rest of the state, Bay Area counties tend to have lower-than-average shares of young children, African Americans, Latinos, and Native Americans—populations that are typically undercounted in the census. Nevertheless, many neighborhoods have relatively high concentrations of young children and people of color—and are still at risk of being undercounted. For example, undercounting people of color in 2020 could significantly misrepresent communities in Richmond, Oakland, East Palo Alto, and Bayview/Hunters Point.
Low responses from noncitizens could lead to an undercount, especially in the South Bay.
Noncitizens may be less likely to respond to the 2020 Census due to the planned addition of a citizenship question and concerns about deportation and privacy. Nearly 18% of people in Santa Clara County are noncitizens, compared to just under 14% statewide. Noncitizens make up about 15% of residents in Alameda and San Mateo Counties as well. In many neighborhoods—including parts of Fremont, Sunnyvale, Cupertino, and Redwood City—more than 30% of residents are noncitizens.
Housing conditions may make some Bay Area residents particularly hard to reach. Several neighborhoods in the East Bay, San Jose, Redwood City, and Santa Cruz have relatively large shares of housing units that are rentals, overcrowded rentals, and/or mobile homes—a reflection of how residents are coping with some of the most expensive housing markets in the country. These conditions can make it harder for the Census Bureau to find and count residents. In some parts of San Jose, for example, one in four rentals is overcrowded. Reaching homeless residents during the three-day window for counting people at shelters, tent camps, and other places will also be critical to an accurate count in the region.

We hope these maps serve as a starting point to help local, regional, and state leaders think about which activities, resources, and partnerships—including language assistance, awareness raising, and community outreach—might be most effective for accurately counting different parts of California. Stay tuned for more posts that examine hard-to-count communities in other regions of the state.