Methodology

Where each number comes from, how far it really runs, and what is not here. Every claim on this page can be checked against a file named on it.

Sources

62 series come from 14 distinct source strings, grouped into 7 families. The family is derived mechanically from the registry's own source field — no series is hand-tagged, so the family counts cannot drift from the provenance.

• World Bank, World Development Indicators — population by age band, dependency ratios, fertility, life expectancy, birth and death rates, under-five mortality, net migration, migrant stock, urban share.
• Maddison Project Database 2023 — population and gross domestic product per head, back to year 1 of the common era.
• Clio-Infra — historical total and urban population, 1500–2000.
• World Inequality Database — total, female and male population by country from 1800.
• United States Census Bureau, American Community Survey five-year estimates — the county panel: population, median age, race and ethnicity, nativity, income, labour force, housing.
• United States Census Bureau, International Database — country population and components, with the publisher's own projections held separately.
• United States Census Bureau, Population Estimates Program — county age bands, 2023 vintage.
• Internal Revenue Service, Statistics of Income — county-to-county and state migration flows from tax filings.

How liveness is reported

Every “through” date on this site is the last real observation in the file. It is never a declared end year, and it is never a projection.

• The Census International Database series carry a source_year_type column that separates historical rows from projections. The projections run to 2100; the last observation is 2024. The site reports the second and labels the first as projections wherever they appear.
• The Statistics of Income migration files key on a filing-year pair (for example 2022-2023), because a migration flow genuinely spans two years. They are not silently collapsed to a single year; the period is the axis label.
• Series are only counted as complete years. Nothing on this site reports a part-year figure alongside full years.

Construction seams

• D001, long-run world population. Rows before 1960 come from the Maddison Project and rows from 1960 come from the World Development Indicators, summed over real countries. The seam is written into the file's own source column. The same file also carries the World Bank's published world aggregate, which is slightly larger than the country sum; both are kept rather than one being quietly preferred.
• Derived series. Three series are explicitly derived from others and say so in their provenance: XS001 from D030–D033, XS002 from D004, XS003 from D008. D058 and D059 are computed from the Population Estimates Program age bands by formula, and the components are shipped in the same file so the ratio can be recomputed rather than trusted.

What is missing, stated plainly

• 2 registered series contain no data. D018 (Population ages 0-14 (% of total) by country), D019 (Working-age population (% of total) by country) ship a header row and nothing else. They are World Development Indicators percentage-of-total variants whose extraction returned zero rows. They remain in the registry and in the catalogue, labelled empty, because deleting them would make the count look tidier while hiding a real gap.
• 3 series have no time axis. D057, D058, D059 are single-vintage cross-sections of United States counties (Population Estimates Program, 2023). They are downloadable but not chartable as a time series, and the explorer says so rather than drawing a one-point line.
• 1 entry is not a series at all. XS001's file holds a single hand-off note for a sibling project. It is counted in the registry and excluded from every observation count.
• The knowledge-base extraction behind this project is preliminary. Ten documents were extracted as text and tables only, not through the full extraction protocol, and the project labels them that way. No number on this site depends on them — every value comes from a statistical source above.
• Two of Gunnar Myrdal's own books could not be obtained (Economic Theory and Underdeveloped Regions, 1957; Asian Drama, 1968), and An American Dilemma is awaiting extraction. This bounds the interpretive material, not the data.
• The construction pipeline is not yet published. See Code.

Validation

The Anu build recorded a schema validation pass, a cross-source reconciliation pass (Maddison against the World Development Indicators) and a ledger health of 100 % green on 2026-07-31. Those verdicts are carried forward from that build and are labelled as such in the manifest; this site does not re-run them. What this site does assert, on every rebuild, is that the manifest and the disk agree in both directions — every file listed exists, and every file present is listed — and that the counts shown on these pages are read from that manifest rather than typed.

Per-series provenance: PROVENANCE.csv. Full registry: series_registry.json (metadata, not a data download).