US Fertility Decline and Washington State Demographics

Pure research. Where US and Washington population trends actually sit in May 2026 — the fertility numbers, the natural-decrease geography, the projections, and what's driving them.

Headline numbers

United States (final 2024 data, released July 2025):

Total fertility rate (TFR) 1.599 births per woman — first sub-1.6 print in US recorded history. Replacement is 2.1; US last met it in 2007.
General fertility rate (GFR) 53.8 per 1,000 women aged 15–44, down 1% from 53.5 in 2023, down 22% from the 2007 peak.
Total births 3,628,934 in 2024 (up 1% nominally from 2023 because more women are aged 15–44; the rate still fell).
Provisional 2025 GFR 53.1, another 1% decrease.

Washington state (April 1, 2025 OFM estimates):

Population 8,115,100, annual growth 79,400 (1.0%) — already a meaningful slowdown vs. the 2010–2020 average of ~98,200/yr.
Births ~81,700 in 2024, the lowest since 2004 (when the state had ~1.8M fewer people).
Washington GFR 51.4 per 1,000 women (2023) — below the national rate.
Natural change (births minus deaths) collapsed from 40,736 in 2010 → 17,654 in 2025. Less than half its level 15 years ago.
78% of 2024–25 growth came from net migration (61,700), only 22% from natural change (17,700).

King County:

Population under 18 peaked at ~456,000 in 2020, fell to ~436,000 by 2022 — first sustained decline after 40 years of growth.
Seattle has the second-lowest fertility rate of major US cities.

The structural picture: postponement plus deepening shortfall

What's actually happening isn't a single story. Two distinct dynamics:

1. Postponement (probably partially recoverable). Births to women under 30 are falling fast; births to women over 35 are flat or rising.

Birth rate at ages 20–24: 52.2 per 1,000 (2025), down from 55.8 in 2024.
Birth rate at ages 25–29: 85.6 (2025), down from 89.5.
Birth rate at ages 40–44: rising.
Childlessness at ages 20–24: ~75% (2014) → ~85% (2024).
Childlessness at ages 25–29: ~50% → ~63%.
Childlessness at ages 30–34: ~29% → ~40%.
The only age group where childlessness fell was 45–50 (16.7% → 14.9%), confirming the shift to later first births.

2. Deepening shortfall (not just delay). Teen births have fallen 76% from the 1996 peak in Washington (8,800 → 2,200). At national level, the 15–19 rate is down 72% since 2007. Pew finds adults in their 20s and 30s now plan fewer children than prior cohorts — desired family size has shifted, not just timing.

The combination matters: if it were pure postponement, the over-40 rates would eventually compensate. They aren't. They're rising but nowhere near the volume the under-30 declines remove. Cohort-completed fertility is on track to fall, not just be redistributed.

The natural-decrease geography

This is where the abstract trend becomes concrete:

2,088 of 3,144 US counties (68%) had more deaths than births in the year ending July 2024.
17 states posted deaths > births in the year ending July 2025 — about a third of the country. Most extreme: Maine, New Hampshire, Vermont, West Virginia.
Nationally, births exceeded deaths by only 518,585 in the year ending July 2025. The 2007 surplus was 1.9 million. Natural increase has collapsed roughly 3.7×.
Projections have been steadily pulled forward. CBO 2024 baseline projected national natural decrease starting 2033, down from the 2023 Census Bureau projection of 2038. After ~2040, net immigration accounts for essentially all US population growth.

The "demographic transition" the US used to describe other countries is now describing the US. Two-thirds of counties are already there.

Washington-specific dynamics

Washington's fertility profile is closer to the European low-fertility cluster than to the US average:

Births trending down since 2017 (OFM), well before COVID.
The fall is concentrated in mothers under 25, with modest offset in mothers 35+ — same postponement signature as the national picture, but starting from a lower base.
The state's GFR of 51.4 trails the US GFR of 53.8 by ~4%.

Migration is doing the work. Washington's continued population growth is almost entirely net migration — 78% in the latest year, and that share has been rising as natural change shrinks. Net migration itself dropped 7,500 from the prior year, which is the early signal worth watching: if migration normalizes downward at the same time natural change continues to shrink, growth slows hard.

Geographic concentration: King (1.4%), Whitman (1.4%, college-town driven), Spokane (1.2%) are the fastest-growing counties. Rural eastern Washington counties are already in natural decrease.

K-12 is the visible downstream effect:

Washington public school enrollment peaked at 1,146,882 in 2019, dropped to 1,091,343 in 2021–22, and is currently 1,098,997 — still ~48,000 below peak.
Elementary grades show the steepest drops (K −2.4%, 1st −3.7%, 3rd −2.4%, 8th −2.5% in the most recent reporting year). OSPI attributes these to lower birth rates and homeschooling growth.
Bellevue closed Wilburton and Eastgate elementaries entering 2023–24 (16 → 14 neighborhood preK–5 schools). Seattle Public Schools deferred closure decisions for 2024–25 but explicitly put 2025–26 on the table. Olympia is considering grade realignment to consolidate buildings.
This is the early structural visible piece — childcare and elementary education are where falling fertility hits public infrastructure first.

What the literature attributes the decline to

The current research consensus is multi-factor; no single explanation does all the work. Strongest signals:

Housing costs (largest single attributable share). Couillard (U Toronto, working paper) attributes ~51% of the TFR decline between the 2000s and 2010s to rising housing costs, estimating ~13 million missing births from 1990–2020 vs. a stable-housing counterfactual. The mechanism is direct (housing eats budget for kids) and indirect (people in roommate or multi-generational arrangements have fewer kids). Median listing price in King County was ~$876,000 in 2023, and PNW housing-cost growth has been steeper than the US average since 2015 — consistent with Washington's below-national GFR.

Childcare cost. Annual per-child childcare expenditure rose from $5,020 (2009) to $7,190 (2015–19 average) nationally; current Seattle-area infant care now runs ~$2,200–2,800/month. People who report having fewer kids than planned consistently cite childcare cost as a top reason. (See pcc-closure-and-the-childcare-collapse for how the supply side is failing in Shoreline specifically.)

Inflation and economic uncertainty. Recent IFS/NBER-adjacent work: a 5pp increase in unexpected inflation correlates with 15–25 fewer births per 1,000 reproductive-aged women. The 2021–2023 inflation shock therefore shows up as a measurable contributor to the 2023–25 fertility prints.

Educational attainment and labor force participation. Postponement of first birth correlates strongly with completed years of education. The increased age-at-first-birth is the single largest mechanical contributor to TFR decline, separate from cost.

Contraception access and intentional childlessness. Teen birth declines are dominated by access + behavioral change, not cost. Roughly 18% of US adults under 50 now say they don't want children (Pew, 2024).

Policy variables that don't show clean signal. Post-Dobbs abortion restrictions: birth-rate changes in restrictive states are small and within noise. The natural experiment doesn't currently show policy as a major fertility lever in either direction. State paid-leave programs: Washington's PFML, in place since 2020, has not produced a measurable bump.

Race/ethnicity composition

National 2024 changes vs. 2023:

Hispanic births +4% (and 64.3 per 1,000 — the highest sub-rate, 2022–24 avg).
Asian births +5%.
Black births −4% (52.9 per 1,000).
American Indian/Alaska Native births continued to decline.
White births ~flat to −1%.

Hispanic fertility rebounding is the largest single offset to the overall decline. If Hispanic immigration falls off — as it has in 2024–25 federal policy — the offset disappears at the moment the underlying trend is steepest.

What the projections imply

Combining current TFR (~1.6), aging Boomers, and current migration trajectories:

Working-age population (25–54) stops growing organically in the 2030s. Whether it grows at all depends entirely on net migration.
Old-age dependency ratio (65+/working-age) rises from ~30 today to ~40+ by 2040. Social Security/Medicare math gets harder, and the political fight over it gets louder.
K-12 enrollment will keep falling through ~2030 in most US states absent migration offset; districts with declining property tax bases will face closures and consolidations earlier.
Higher ed faces the "enrollment cliff" already much-discussed — the 2007 birth-rate peak hit college-entry age in 2025–2026; the cliff is real and already arriving.
Childcare sector is structurally hollowing out — fewer kids per region, plus rising labor costs, plus inelastic willingness-to-pay. Net result is closures concentrated in areas where supply was already thin (see Washington Standard reporting on rural and exurban WA childcare deserts).

What this can't yet resolve

Open questions worth flagging:

Is the postponement reversible at scale? Some highly-educated cohorts are catching up at 35–44, but completed cohort fertility for women born in the 1990s is still on track to be below their stated desired family size. The "missing children" gap (desired – actual) is widening. No country has cleanly reversed it once it opened.
Pro-natal policy efficacy. Hungary, Russia, France, South Korea, Japan have all tried versions. Best result is roughly +0.1–0.2 TFR for sustained effort, usually fading. No country with sub-1.7 TFR has pushed back above 2.0 via policy.
Migration's political ceiling. US projections assume continued net immigration of ~1M/yr (CBO baseline). If that compresses for political reasons, the population trajectory changes meaningfully within a decade — not in 2050. The state-level data already shows this: WA migration dropped 7,500 YoY in 2024–25.
The housing-fertility causal chain. Couillard's 51% attribution is contested; some economists argue the causation runs through urban concentration (denser housing markets → later/fewer kids) more than absolute cost. Doesn't change the trend but changes which policies might address it.
Climate, AI labor displacement, and existential-risk perception. Survey data shows rising shares of young adults citing "future of the world" as a reason not to have kids. Hard to know how much weight to give self-reported reasons vs. observed cost behavior.

US Fertility Decline and Washington State Demographics

US Fertility Decline and Washington State Demographics

Headline numbers

The structural picture: postponement plus deepening shortfall

The natural-decrease geography

Washington-specific dynamics

What the literature attributes the decline to

Race/ethnicity composition

What the projections imply

What this can't yet resolve

Key sources