Africa Center is a reference site, not a research institution: we compile published statistics, we don't generate them. The trust readers can place in any figure on the site therefore reduces to two questions — "where did this number come from?" and "what did Africa Center do with it before publishing?" This page answers both.
Source hierarchy
For every indicator on a country profile — population, nominal GDP, GDP per capita, life expectancy, literacy rate, urbanisation, growth rate — we start from a fixed source hierarchy. When the same indicator is published by more than one body, we prefer the source higher on the list:
- The country\'s own national statistics office, when it has published a recent census, household survey, or annual statistical yearbook covering the indicator.
- The World Bank Open Data portal, which standardises a wide range of indicators across countries and updates them on a known schedule.
- The International Monetary Fund\'s World Economic Outlook database for macroeconomic figures — nominal GDP, GDP per capita, growth rate — where its country desk officers have visibility we couldn\'t match elsewhere.
- The relevant United Nations specialised agency for sectoral indicators: UNESCO Institute for Statistics for literacy and education, the UN Population Division for demography, the World Health Organization for life expectancy and health, UN-Habitat for urbanisation.
- The African Development Bank\'s African Statistical Yearbook as a regional cross-check, particularly for indicators specific to the continent. The institutional context — which body publishes what — is summarised in the AU and the RECs.
If only one source publishes a given indicator for a given country, that source is used and identified. We avoid third-party aggregators that strip out the original citation; the index of primary sources we recommend is on the data sources page. For the resulting numbers laid out side by side across all five regions, see the regional comparison.
What we do when sources disagree
Sources frequently disagree about African data, sometimes by surprisingly large margins. The most common reasons are:
- Different reference years. The World Bank may publish 2024 figures while a national release covers 2025; the IMF\'s outlook may already include 2026 forecasts. We always pick the most recent actual measurement, not a forecast.
- Different definitions. "Urbanisation" can mean the share of population in legally-defined urban municipalities, or the share in places above a population density threshold. We use the World Bank / UN-Habitat definition consistently.
- Different exchange rates. Nominal GDP in USD is sensitive to the rate used to convert local-currency GDP. We use the IMF\'s reported nominal-USD figure, which uses an average annual exchange rate.
- Pending revisions. Statistical agencies revise older figures when new census or survey data is published. We use the latest revised series.
When a meaningful discrepancy survives those rules — say, a national census suggesting a population materially different from World Bank or UN estimates — we publish the national figure and note the discrepancy on the country profile. We do not silently average sources.
Update cadence
Country indicators are reviewed when the principal source publishes a new release. World Bank Open Data refreshes most indicators annually; the IMF\'s World Economic Outlook updates twice a year (April and October), with smaller country-specific updates in between; UN agencies typically publish on a one- to three-year cycle depending on indicator. We aim to update each country profile within a fortnight of a major release.
Every page that carries indicators carries a visible "Last reviewed" date. That date is the most recent moment a human checked the figures on the page against the principal source. It does not promise that every figure is the most current possible — only that, as of the date shown, the figures had been checked and were aligned with the source we cite.
Revisions and corrections
We treat corrections as a priority. If you spot a figure that disagrees with a primary source you can link to, write to [email protected] with the URL of the page in question and the URL of the primary source. We typically apply corrections within a week.
When a source itself revises a figure substantially — for example, a country republishes a census with a markedly different population total — we replace the figure on the country profile and update the "Last reviewed" date. We do not maintain a public revision log.
Indicator definitions
To avoid repeating the same definitions on every page, we keep them in a central glossary. The glossary spells out, for instance, the difference between nominal GDP and GDP at purchasing-power parity, what "literacy rate" precisely measures, why "life expectancy at birth" can change suddenly during a public-health shock, and how the urban / rural split is drawn. The glossary is the authoritative reference within the site.
What we do not publish
To make the editorial line clear:
- We do not publish forecasts. Every figure on the site is a measured or estimated value for a past or current period; projections belong to the original source organisations.
- We do not publish editorial rankings driven by our own scoring. Where rankings appear — "top 10 economies by GDP", for example — they are direct sorts of values from primary sources, with the sort criterion stated.
- We do not publish proprietary indices of our own making.
- We do not publish opinion or commentary on policy. The site is descriptive.
Checklist before a page goes live
Each substantive page that contains country indicators is checked against this list before publication or after a major revision:
- Every figure can be traced to a primary source listed in data sources.
- The figure is the most recent actual measurement, not a projection.
- If sources disagree materially, the discrepancy is disclosed on the page.
- Indicator definitions match the central glossary.
- The "Last reviewed" date reflects the most recent check, not the last unrelated edit.
Common mistakes when using the data
Two errors come up often when readers reuse Africa Center figures, and both are easy to avoid:
- Mixing nominal and PPP GDP. The headline GDP we publish is nominal — converted to USD at market exchange rates. PPP GDP figures from the IMF are larger for most African economies and are not directly comparable. If you cite a value from the site, cite it as nominal. The full explanation of nominal-vs-PPP and why GDP rankings move is on reading African economic data.
- Treating a revised series as a contradiction. When a country revises its GDP series — Nigeria, Ghana, and Kenya have all done this in recent years — earlier figures change retroactively. A figure you cited in 2022 may now be different on the source\'s own page. Always cite the version you used and the date you accessed it. The how to cite page has examples; the longer treatment is on why African statistics get revised.
Last reviewed: 28 April 2026.