New Data Release from 2020 Census

A First Look at the Demographic and Housing Characteristics File in Southern California and Beyond 


The United States Census Bureau recently released a critical update to its 2020 numbers, offering additional data on the demographic and housing characteristics of local communities across the country. 

This data puts known trends in historical perspective and shows how differently Southern California, and Los Angeles County in particular, has evolved from the rest of the nation in the last generation. 

The 2020 Census Demographic and Housing Characteristics (DHC) data files were released to the public on Thursday, May 25. The DHC file includes detail on age, sex, race, ethnicity, families, households, homeownership, and housing occupancy/vacancy, and provides the most comprehensive and granular information available for the United States population. 

Until now, the only data available from Census 2020 was the “Redistricting File,” which was released in August 2021 and provided just enough data to inform the drawing of new congressional districts (SCAG’s analysis of that data release is available here). The release of the DHC file was delayed multiple times due to challenges from both the pandemic and the introduction of new privacy measures designed to make it harder to identify individuals’ information.  

The 2020 Census was intended to count everyone “once, only once, and in the right place.” Overall, the population count was extremely accurate nationwide and in California. However, it is worth noting that there are known undercounts in the data, notably among young children, Black, Hispanic/Latino and Some Other Race populations, and among American Indian/Alaska Natives living on reservations.  

In some instances, Southern California mirrors national trends such as a gradual drop in homeownership, an accelerated decline in households with children and aging. In other ways, the region stands out further. Southern California is renter-heavy, but for the first time, a majority of households with children are now renters, suggesting that the lived experience of the region’s children will be different than in past generations and in other parts of the country.  

The majority of young and middle-aged householders are now renters as well, indicating that homeownership in Southern California is not increasing through the life course nearly as much as it does nationally. Nationwide, an aging population results in more who live alone, however, in Southern California the share of single-person households is fairly stable. This trend could be due to a corresponding increase in living with roommates or other relatives (e.g., adult children) as well as increased male life expectancy. 

What follows are twelve data points and highlights from this release across the six counties in Southern California, the rest of California and the nation.  

Homeownership Overall  

Homeownership has steadily fallen below its 2000 highs in most places but remains substantially higher in the nation as a whole (63.1 percent) than in Southern California (52.4 percent). Los Angeles County remains the lowest (45.6 percent), and is the only place shown where homeownership declined in each of the last three decades. Orange County had the largest decrease in homeownership rate in the last decade (59.3 percent to 56.1 percent)—this is likely partly due to the increase in multifamily construction in this characteristically suburban county. 

Homeownership in White Non-Hispanic Population

Most household forecasts, including SCAG’s, consider race/ethnicity and age separately due to wide variations. In most places, homeownership rates of the white, non-Hispanic population are several percentage points higher than the population as a whole. Comparison with the previous figure shows that the difference has grown over time in the United States. (a gap of 4.9 percent in 1990 to a gap of 8.2 percent in 2020) and similarly in Orange, Riverside, and San Bernardino counties (3.3, 2.9, and 4.6 percent, respectively). In contrast, the difference shrank modestly in Los Angeles County (a gap of 8.4 percent in 1990 to a gap of 7.2 percent in 2020).

Homeownership By Age

The homeownership rate typically increases through the life course, with renting being more prevalent among young adults and less prevalent among the oldest ages. The homeownership rate for seniors 75+ is 88 to 94 percent in all places and shows very little differentiation between Southern California and the state or nation. However, younger groups see major differences — nationally, 38.3 percent of young adults ages 25 to 34 are homeowners, while only 24.2 percent in Southern California are homeowners. This difference persists among middle-aged adults and younger seniors, where homeownership rates are several percentage points below the nation.

Households With Children

Resulting from declining fertility rates, far fewer American households have children than in 2000, when this statistic reached a high point in most places in California. The decline was greater in the SCAG region than in the rest of the state and nation. In Imperial, Los Angeles, San Bernardino and Ventura counties, households had fewer children by roughly 10 percentage points than in 2000.

Homeownership Of Households With Children

More children have grown up in renter households since 2010. While the majority of American households with children owned their homes in 2020, a slight majority of Southern California households with children are renters. This trend is most extreme in Los Angeles County where only 43.5 percent of households with children are owners. The decline in homeownership of households with children is most notable in Orange and Ventura counties (4 to 5 percentage points).

Total Household Formation Rate

The household formation rate is defined as the number of households divided by the number of people ages 15 and above. This statistic reflects choices made in living arrangements such as where and with whom to live. The slowly developing, and now widely acknowledged, housing shortage in much of Southern California was reflected in steady drops in household formation rates from 1980 to 2010. However, consistent with recent years’ American Community Survey data, household formation rates were generally stable between 2010 and 2020 in the SCAG region (41.2 percent to 41.4 percent) as well as most of the region’s counties. The United States as a whole did not see the same historical decreases as the region but saw a 0.5 percentage point increase in the share of adults who are the head of their own households in the last decade. In contrast to these increases, the non-SCAG portion of California continued a slight headship rate decline.

Household Formation Rate By Age

Both homeownership and household formation rates are well below national levels in the state and region for young adults (ages 25 to 34). However, while older seniors’ (75+) homeownership rates in Southern California were on par with the nation (roughly 90 percent), older seniors differ from the country in household formation – 59.7 percent versus 66.9 percent.

Single-Person Households

Most Southern California counties have a far lower share of people living alone than nationally. This likely results in part from a slightly lower senior citizen population share (shown in a separate figure). However, while the senior share of the population grew tremendously in all areas in the last decade, the share of single-person households did not. This likely suggests countervailing forces reducing the number of single-person households amongst the rest of the population, which could include adult children continuing to live with parents later in life, more roommates living together or increased male life expectancy.

Multi-Generational Households

Average household sizes in Southern California increased from 1990 to 2010, then decreased over the most recent decade. In contrast, the counties of Riverside and San Bernardino saw relatively consistent increases in household size over this period while in the United States household sizes decreased gradually.

Average Household Size

The instance of three or more generations (e.g., parents, children, and grandparents) sharing a household has been a topic of conversation in demographics and housing planning given an ageing population, housing shortages and cost burdens. It also tends to be more pronounced in communities of recent immigrants or diasporas from Latin America and Asia. This is reflected in multigenerational housing shares in Southern California which far exceed the levels in the rest of the state and the nation as a whole.

Population Share Of Senior Citizens

While senior citizen shares increased gradually in most places between 1990 and 2010, they increased substantially – in most instances 3 to 4 percentage points – between 2010 and 2020. The 2010s were a decade of record low fertility rates in much of the country leading to a much older population age structure and inviting concerns over old-age dependency and retirement solvency.

Median Age

This trend is related to the increasing share of senior citizens. Most Southern California counties have median ages below the national median of 39, though Imperial and San Bernardino counties are much younger than the rest of the state and nation.

Report prepared by:

Kevin Kane, PhD, SCAG
Huixin Zheng, PhD, SCAG
Dowell Myers, PhD, USC Population Dynamics Research Center
Beth Jarosz, Population Reference Bureau