Country Data Guides
Educational resources to help you understand and interpret global development data.
All guides reference data from the World Bank World Development Indicators and the WHO Global Health Observatory, covering 217 countries and territories across 45 indicators.
Understanding Development Indicators
What the World Bank WDI tracks — GDP, population, life expectancy, education, and poverty — and how these measures reveal development progress.
How to Compare Countries Fairly
PPP vs. nominal GDP, per capita measures, and the most common mistakes people make when interpreting cross-country statistics.
Global Health Indicators Explained
What WHO GHO data measures, key health metrics like life expectancy and infant mortality, and how health outcomes correlate with economic development.
Richest vs. Poorest Countries
GDP per capita rankings for the world's wealthiest and least wealthy nations, purchasing power parity context, and what drives the income gap.
Global Health Indicators Compared by Region
Life expectancy, infant mortality, maternal mortality, and healthcare spending compared across world regions — with data tables and regional patterns.
OECD Health Systems Compared
How 38 OECD countries compare on healthcare spending, physician density, hospital capacity, life expectancy, and infant mortality — with live 2025 data tables.
Explore the data: Browse all countries · View indicators · Compare two countries
Methodology
Every guide on this page is written to explain a specific dimension of the data sources PlainCountries uses — Source: World Bank Open Data, Source: WHO Global Health Observatory, Source: ILO ILOSTAT, and Source: OECD.Stat — and how they fit together.
Writing standard. Guides use plain-English explanations backed by named indicators and direct links to the source agency. We do not summarise what secondary sites say; we summarise what the primary source agency publishes and cite the underlying indicator code so the reader can verify the claim.
Update cadence. Guides are updated when the underlying data release changes a methodology note, when a new indicator is added, or when an agency deprecates a series. Each guide shows its last-updated date at the top of the page and lists the specific data vintages it reports.
No imputation. When a guide reports a headline figure for a country, it is the value published by the source agency for a specific observation year. We never carry forward stale values or estimate missing data; where a value is unavailable, the guide says so explicitly.
For the full site-wide methodology, see the methodology page or the browse directory.