United States
Available since: Phase 5 (2026)
All US reference tables follow the shared demographic data model (age 0–100 × sex, long CSV).
Baseline
Section titled “Baseline”The baseline is the configuration the tool opens with — official Census Bureau, SSA and NCHS reference data. Total fertility rate ≈ 1.6; base population ≈ 340.1 M.
| Variable | Baseline data set | Vintage | Notes |
|---|---|---|---|
| Population | USA 2024 (Census) | 2024 | start-of-projection |
| Fertility | NCHS 2023 | 2023 | held flat |
| Mortality | SSA 2023 | 2023 | improves −0.5%/yr ×10y |
| Migration | Census projection 2024 (constant) | 2024 | held flat |
| Sex ratio at birth | 1.05 | — | standard biological ratio |
Any input can be changed or fine-tuned — see how to model demography.
Available data sets
Section titled “Available data sets”The dropdowns in the tool currently offer, per variable:
-
Population — USA 2024 (Census): US Census Bureau, Population Estimates Program, national resident population by single year of age and sex (vintage 2024).
-
Fertility — NCHS 2023: National Center for Health Statistics, National Vital Statistics Reports Vol. 74 No. 3, age-specific birth rates by 5-year maternal age group, graduated to a single-year-of-age curve (no single-year source is publicly published).
-
Mortality — SSA 2023: Social Security Administration period life table (Social Security area population), qx by single year of age and sex.
-
Migration — four options: the default Census projection 2024 (constant, held flat), plus three SSA scenario presets from the 2025 OASDI Trustees Report:
Scenario Net immigration path SSA Low-Cost (Alt. I) ~2.9M/yr (2025) declining to ~1.7M/yr SSA Intermediate (Alt. II) ~2.1M/yr (2025) declining to ~1.2M/yr SSA High-Cost (Alt. III) ~1.3M/yr (2025) settling around ~0.8M/yr The Fertility and Mortality blocks each offer their own matching SSA preset too — its own dropdown per section, independent of Migration’s scenario and of each other, so any combination can be explored (e.g. Low-Cost fertility with High-Cost mortality), not just the three matched alternatives:
Scenario Ultimate TFR Mortality decline SSA Low-Cost (Alt. I) 2.10 0.27%/yr SSA Intermediate (Alt. II) 1.90 0.74%/yr SSA High-Cost (Alt. III) 1.60 1.26%/yr Picking the same alternative in all three sections reproduces SSA’s own published assumptions, not a guaranteed match to SSA’s own reported population total — the Intermediate preset tracks SSA’s Social Security area population within ~0.1% through 2030, then drifts above it (+5% by 2050) since our engine’s cohort mechanics don’t fully reproduce SSA’s own mid-century growth deceleration. See the engine data README for the full control-point tables and sourcing.
Additional data (History tab)
Section titled “Additional data (History tab)”| Series | Coverage | Source |
|---|---|---|
Mortality qx / life tables (M/F/Both) |
1933–2024 | HMD — United States |
| Deaths by age × sex | 1933–2024 | HMD — United States |
These power the life-expectancy history (with projection overlay), the
mortality heatmap (isolines / age guides), qx-at-ages and the animated deaths
tree. No WHO HALE series is shipped for the United States yet, so the HALE
chart is unavailable. The recipient_share reference set (OASDI
beneficiaries as a share of population) is sex-neutral — SSA’s public age
breakdown isn’t split by sex — see
the engine data README
for the full source list and known limitations.
Pensions
Section titled “Pensions”The USA’s Pensions Coverage pass — contributors and beneficiaries by headcount, by regime/benefit type — see how to model pensions for the general walkthrough; the figures below are the tool’s editable defaults. Macro and Finance (real dollar figures) are documented in their own sections further down this page.
Contributors
Section titled “Contributors”~180.7 M workers had OASDI-taxable earnings in 2022, split across two regimes:
| Regime | 2022 headcount |
|---|---|
| Wage & salary employees | ~159.4 M |
| Self-employed | ~21.2 M |
Beneficiaries
Section titled “Beneficiaries”~67.1 M people drew an OASDI benefit in December 2023, across five types, plus 7.4 M more on Supplemental Security Income (a separate, needs-tested register — SSI and OASDI overlap for ~2.5 M people who receive both, so the two totals aren’t additive into one “persons” figure):
| Benefit type | Dec 2023 headcount |
|---|---|
| Retired workers | 50,147,679 |
| Disabled workers | 7,365,987 |
| Spouses | 1,984,227 |
| Widow(er)s | 3,796,684 |
| Children | 3,782,389 |
| Supplemental Security Income (SSI) | 7,425,331 |
Unlike Spain, the USA has no Clases-Pasivas-equivalent closed cohort
modeled yet (a CSRS federal-employee analog exists but wasn’t sourced this
pass) and no effective-retirement-age modeling (the USA’s own statutory age
varies by birth year rather than a flat threshold) — both are documented,
deliberate gaps, not silent omissions. See
docs/data-sources/usa-pension-reference-data.md in the project repository
for the full source-by-source breakdown.
The USA’s Macro layer (GDP/inflation/wage/pension growth) uses real, verified figures throughout — unlike Spain’s own Macro data, where only GDP is a real reported figure and the other three drivers are still placeholder.
| Driver | 2024 value | Ramps to (long-run target) | Source |
|---|---|---|---|
| GDP growth (nominal) | 5.34%/yr | 4.0%/yr over 10 years | BEA (nominal GDP level) |
| Inflation (CPI-W) | 2.84%/yr | 2.4%/yr over 3 years | SSA 2025 Trustees Report |
| Wage growth | 4.21%/yr | 0.89 × GDP growth over 10 years | SSA 2025 Trustees Report |
| Pension growth | 3.2%/yr | 1.0 × CPI-W over 3 years | Social Security COLA (statutory) |
GDP size (nominal level) defaults to $29,298.0bn for 2024 (BEA). Pension
growth’s coefficient is exactly 1.0, not an approximation — the Social
Security Cost-of-Living Adjustment is, by law, the CPI-W percentage change,
so this driver reproduces the actual statutory formula rather than modeling
an approximation of it. See docs/data-sources/usa-macro-reference-data.md
in the project repository for the full source-by-source breakdown. This
feeds both the standalone Macro tab and, new this pass, the Finance pass
below.
Finance
Section titled “Finance”The Pensions Finance pass (contribution revenue, benefit expenditure, reserve accumulation/drawdown, Present Value of obligations — chains a pinned Coverage scenario to a pinned Macro scenario) is now available for the USA too, with real figures throughout:
| Item | Value | Source |
|---|---|---|
| OASDI payroll tax rate | 12.4% (both regimes) | Social Security Act (FICA/SECA) |
| Average taxable earnings, Wage & salary (M/F) | $59,531 / $43,645 | SSA Annual Statistical Supplement (2021 median by sex, scaled to match 2022’s real reported mean) |
| Average taxable earnings, Self-employed (M/F) | $26,762 / $17,793 | same source/method |
| Average monthly benefit, six benefit types | $620–$2,106 by sex | SSA Annual Statistical Supplement, Dec 2023 |
| Combined OASI/DI Trust Fund balance, seeded | $2.72 trillion | SSA 2025 Trustees Report (end of 2024) |
| Reserve drawdown | 0.8% of GDP/yr from 2026 | calibrated to deplete ~2034, matching the Trustees Report’s own projection |
Unlike Spain’s benefit amounts (annualized ×14, “pagas extraordinarias”),
Social Security pays 12 times a year — the USA instance annualizes ×12. It
also has no ClasesPasivas-equivalent entry (Coverage doesn’t model a
CSRS-equivalent closed cohort yet, see the Pensions section above), so the
Expenditure block simply has no such category rather than a zero-value
placeholder one. See
docs/data-sources/usa-pension-finance-reference-data.md in the project
repository for the full source-by-source breakdown, including exactly how
the average-earnings figures were derived (SSA’s own by-sex breakdown is
median, not mean, which would otherwise understate PAYG revenue by roughly
a third).
Activated models
Section titled “Activated models”| Model | Status |
|---|---|
| Demography | ✅ Active |
| Pensions | ✅ Active (Coverage + Finance) |
| Disability | 🔜 planned |
| Long-term care | 🔜 planned |