Data & Math: Data Sources & Demographic Methodology
TerraRoll uses public international statistical releases in a probability model covering 172 countries and territories. The reference data and fictional game model serve different purposes; sources, observation years and transformations are documented below.
Annual Births, Population & Sex-Specific Life Expectancy: United Nations World Population Prospects (UN WPP) demographic indicators, female-to-male longevity differentials, and under-5 child survival tables.
Household Purchasing Power & Inequality: World Bank World Development Indicators (WDI) GNI per capita (PPP, current international dollars) paired with Gini index income dispersion distributions.
Schooling, Wellbeing & Digital Access: UNESCO UIS and UNDP Human Development Report expected years of schooling, ITU individual internet penetration, urbanization share, and World Happiness Report life evaluations.
Bilateral Migration Corridors: UN DESA International Migrant Stock origin-to-destination matrices across major regional pathways.
Normalization, Fallbacks & Educational Scope
The reference export uses each indicator’s latest available recorded observation; missing fetched observations remain null. The game may use model fallbacks to keep a fictional life playable. Those estimates are not new observations about a country. Download /country-data.json for reference values and their declared units.
Simulated lives are fictional stories inspired by aggregate national distributions, never predictions about any real person. Within-country regional diversity, community mutual aid, and individual choices always reach far beyond macro averages.
Indicator Sources, Observation Years & Reuse
Compiled by TerraRoll from World Bank World Development Indicators; UN DESA statistical releases; UNDP Human Development Reports; Our World in Data; and the World Happiness Report. Our World in Data also processes underlying UN IGME, Gapminder and other provider series. Credits and source-specific terms are recorded in the source register; these institutions do not endorse this game.
Observation years differ by country and field. Birth counts may be calculated from a birth rate and population; game life-expectancy estimates and birth shares are derived values. Missing reference observations remain null. The Taiwan under-five mortality observation is from 2010: its retained 0.54 percent is converted to 5.4 deaths per 1,000 live births.
This mixed-source export is not offered under a single blanket licence. Some retained provider terms and the infant-mortality series identifier remain unresolved. Read the individual source entries before reusing data.