Brookings Institution (March 2026)
Measuring Housing Through a Single Household Head
Housing affordability debates often focus on how many homes a country needs to address shortages and rising costs. However, the way housing statistics are constructed can significantly shape how policymakers interpret the problem. The Brookings report Who We Count Shapes How We Measure Housing Supply and Affordability argues that conventional housing metrics rely heavily on the characteristics of a single “household head,” which may distort how housing needs and cost burdens are understood.
Most housing supply projections begin with estimates of household formation. Researchers translate population trends into housing demand using headship rates, defined as the share of adults designated as the head of a household in survey data. These projections then inform estimates of how many housing units are required to meet demand.
However, this approach simplifies complex living arrangements. As the report explains, when statistics rely on the characteristics of a single household head, they may obscure important demographic differences among adults living in the same household. This methodological choice shapes both how housing demand is measured and how housing affordability is evaluated.
Nearly Half of Adults Are Not Household Heads
One of the report’s central findings is that a large share of adults are not represented directly in housing statistics. According to the 2024 American Community Survey (ACS), only 50.9 percent of adults aged eighteen and older are classified as household heads, meaning roughly half of adults are represented only indirectly through the characteristics of another person in the household.
The report illustrates that non-head adults frequently differ from the designated head along key demographic dimensions such as age and education. For example, younger adults often live in households where the head belongs to an older age group. Similarly, differences in educational attainment within multi-adult households can be significant.
Because household-level statistics rely on the head’s characteristics, these differences are often overlooked in standard measures of housing demand and affordability. As a result, demographic patterns within households may be misrepresented in policy discussions and research.
Multi-Adult Households Reveal Hidden Demographic Differences
The report highlights that the majority of households include more than one adult. In these multi-adult households, relying on a single reference person can mask meaningful variation in living arrangements.
For instance, when the household head is a young adult aged 18–29, other adults in the household are usually in the same age group. However, when the head is older, the age distribution of other household members becomes much more varied. According to the analysis, nearly 40 percent of other adults in households headed by individuals aged 30–54 fall into a different age group, while over 40 percent of adults living in households headed by someone aged fifty-five or older are younger than the head.
Educational differences can be even more pronounced. In households where the head has lower educational attainment, many other adults possess higher levels of education. Conversely, when the head has a college degree, many other adults may have less education. These variations suggest that using the household head as a proxy for all adults can lead to misleading conclusions about demographic patterns in housing demand.
Housing Cost Burdens Are Often Misidentified
The methodological limitations of head-based statistics also affect how housing affordability is measured. Housing cost burden is typically defined at the household level, with households considered burdened if housing costs exceed 30 percent of income and severely burdened if costs exceed 50 percent.
When affordability statistics rely on the head’s characteristics, they can misidentify which demographic groups are most affected by high housing costs. The report demonstrates that young adults represent a larger share of the cost-burdened population than head-based statistics suggest.
For example, among households spending more than 30 percent of income on housing, only 14.5 percent of household heads are young adults, yet 21.8 percent of adults living in those households are young adults. This discrepancy indicates that housing pressures facing younger populations may be significantly underestimated in conventional analyses.
Measurement Choices Shape Housing Policy Narratives
The authors emphasize that statistical frameworks play an important role in shaping housing policy debates. Headship rates are fundamental to estimating housing demand because they convert population counts into estimates of the number of households and therefore the number of housing units required.
However, headship rates are not fixed. Living arrangements change in response to economic conditions, housing prices, and social preferences. When housing costs rise, adults may delay forming independent households or move into shared living arrangements. In such cases, declining headship rates may reflect housing constraints rather than reduced housing demand.
The report concludes that researchers and policymakers should consider who lives within a household (not only who heads it) when measuring housing affordability and housing supply needs. Expanding the analytical focus to include all adults within households can provide a more accurate understanding of housing pressures and improve the design of housing policy responses.
Reference
Patel, E., Rajan, A., & Tomeh, N. (2026). Who we count shapes how we measure housing supply and affordability. Brookings Institution. https://www.brookings.edu/articles/