Lead: A new research note by UC Irvine PhD student Schuyler Louie and San Francisco Fed researchers John Mondragon, Rami Najjar, and Johannes Wieland finds that rising average incomes — particularly at the top of the distribution — explain house-price growth more than shortages of housing units. Using metro-area data from the mid-1970s through 2024, the authors report that average income growth tracks house-price growth closely, while housing supply growth aligns with population change rather than income. The finding challenges the widely held policy focus on increasing supply as the principal remedy for affordability problems in places such as California.
Key Takeaways
- Researchers analyzed U.S. metro data from the mid-1970s to 2024 and report a nearly one-for-one relationship between average income growth and house-price growth over that full period.
- From 2000 onward, home prices outpaced median incomes substantially, marking a divergence from earlier decades.
- The study finds almost no correlation between average income growth and net growth in housing units across metro areas between 2000 and 2020.
- Housing supply growth is strongly and positively associated with population growth across essentially all metro areas in the sample.
- Nearly all metro areas examined recorded housing-unit growth that exceeded population growth, including high-cost markets such as Los Angeles and San Francisco.
- Two types of demand appear important: demand for higher housing quality (driven by income gains) that raises prices but not unit counts, and demand for additional units (driven by population gains) that raises both supply and prices.
- The authors conclude that supply-side regulatory reforms alone may have limited effects on affordability unless policymakers also address demand-side income distribution and labor-market changes.
Background
For decades, economists, policymakers and industry groups have prioritized increasing the housing stock — through zoning reform, streamlined permitting and incentives for construction — as the primary lever to improve affordability. That consensus rests on the simple supply–demand idea that more units should reduce prices or at least slow price growth. High-profile debates have framed states like California as supply-constrained, while Texas and other Sun Belt states are often portrayed as more permissive and therefore more affordable.
At the same time, U.S. income dynamics have shifted. Since around 2000, higher-income households and top-end wages have grown faster than incomes nearer the middle, raising broader questions about how changes in income distribution influence housing markets. Migration flows, local labor-market specialization and amenities also concentrate higher earners in particular metro areas, complicating the simple supply-only story. This research re-examines those dynamics using metro-level data spanning roughly five decades.
Main Event
The authors — Louie, Mondragon, Najjar and Wieland — compiled metropolitan data stretching back to the mid-1970s and tracked trends through 2024. Their core finding is that average income growth is strongly correlated with house-price growth across metros, while there is little relationship between average income growth and housing-unit growth. In plain terms, when average incomes rise, prices tend to rise in step; that rise does not appear to trigger proportional increases in the number of homes.
Conversely, the growth in housing units is closely related to population growth. The data show that regions experiencing more incoming households tend to add more housing units, implying that quantity adjustments respond to household formation and migration patterns rather than to rising incomes per se. This pattern holds in expensive markets such as Los Angeles and San Francisco—places that still added housing units at rates often exceeding population growth.
The note distinguishes two demand mechanisms. First, when households become wealthier without substantial changes in household formation, demand shifts toward better housing quality—renovations, moves to higher-quality neighborhoods or upgrades—that push up prices without increasing unit counts. Second, when population growth brings more households with roughly similar average incomes, demand for additional units rises and developers respond by supplying more homes.
Analysis & Implications
If average income growth — particularly gains concentrated at the top — is a main driver of house-price inflation, the policy implications are substantial. Traditional supply-focused tools (e.g., zoning relaxation, faster permitting) may blunt some price pressure but will not address demand-side forces that increase willingness to pay. In markets where high-earner income gains are concentrated, prices can rise even when supply expands, because richer buyers bid up quality and location premiums.
This shifts attention toward labor-market and fiscal levers. Policies that influence the distribution of earnings across occupations and regions — from tax and transfer systems to investments in local job creation across a broader set of industries — could be as important for affordability as reforms to land-use rules. Localities that attract high-wage industries without commensurate increases in middle-income employment may see persistent affordability pressures.
The finding that supply growth closely follows population growth suggests that migration and household-formation patterns are key moderators of whether new construction meaningfully increases unit counts. For cities, that means sourcing policies to manage inflows (housing for new workers, transit-linked development) could be more effective than supply-side deregulation alone. It also implies that debates blaming NIMBYism or permitting delays for price rises may overstate the role of supply constraints in many metros.
Comparison & Data
| Period | Income–House Price Relation | Income–Supply Relation | Supply–Population Relation |
|---|---|---|---|
| 1975–2000 | Close tracking (prices ~ incomes) | Weak/uncorrelated | Positive |
| 2000–2024 | Prices outpaced median incomes; avg. income tracks prices one-for-one | No clear relationship (2000–2020) | Strong positive |
The table summarizes the qualitative patterns reported by the researchers: before 2000, house prices and incomes moved together, while after 2000 prices accelerated relative to median incomes. Across both eras, housing-unit growth is most strongly tied to population change rather than to income growth, a distinction that reshapes how we interpret regional housing dynamics.
Reactions & Quotes
“There is almost no connection between average income growth and growth in housing supply.”
Schuyler Louie et al., San Francisco Fed research note
That line captures the note’s central empirical claim: income gains do not mechanically translate into more units. The authors frame this as a challenge to policies that focus narrowly on boosting unit counts without addressing who benefits from income growth.
“Housing supply growth has a strong positive relationship with population growth.”
Schuyler Louie et al., San Francisco Fed research note
This observation underlines that demographic change — the arrival of new households — is the more consistent predictor of added housing units across metro areas in the study.
Unconfirmed
- The extent to which local land-use restrictions (NIMBYism) directly reduced unit growth in any specific metro remains unverified by the note; the paper emphasizes correlations rather than causal identification for every mechanism.
- The precise share of price increases attributable to renovation and quality upgrades versus outright purchases by higher earners is not fully quantified in the note.
- Whether short-term speculative investment or financial factors (e.g., mortgage conditions) materially altered the income–price relationship in certain years is not resolved in this analysis.
Bottom Line
The research adds weight to a reframing of the U.S. affordability challenge: in many metro areas, rising average incomes — concentrated gains at the top — are a principal engine of house-price growth, while housing-unit growth tracks population change rather than income. That means policies aimed solely at increasing unit counts may have limited success unless paired with measures that address demand-side income distribution and labor-market structure.
For policymakers, the takeaway is practical: combine supply-side reforms that ease construction where population growth warrants more units with broader fiscal and labor-market measures that limit extreme income concentration in particular locales. Absent such a two-pronged approach, high prices are likely to persist even when jurisdictions increase permitting or relax zoning rules.