# Data sources and simulation method

> Dataset provenance, weighting, units, snapshot dates and limits of the 172-country life simulation.

Canonical page: https://1in8bn.com/reference/data-and-method/
Reviewed: 2026-10-25. Language: English.

## Country-data provenance

The 172-country statistical dataset comes from the MIT-licensed rollroyces/born-somewhere repository, commit c7cd3109456ceb22415cc9eba3f8f7cf73efa1b1, retrieved on 20 October 2026. Third-party notices record this snapshot and the applicable license.

The reference repository identifies UN World Population Prospects 2024, World Bank WDI, WHO, UNESCO UIS, UNDP HDR, ILO, UNAIDS, UNODC, UNICEF and the World Happiness Report 2024 as statistical sources. This site uses the reference snapshot; it does not claim a new live verification of every underlying indicator.


## Birthplace weighting

- Annual-birth weighting samples countries in proportion to the dataset’s annual births.
- Population weighting samples countries in proportion to the dataset’s population.
- Equal-country weighting gives each included country an equal starting chance.
- The included-country catalog and statistical estimates simplify the world; coverage is not a political or territorial claim.

## Units and missing values

In the source data, pop is measured in thousands; im and u5 are rates per 1,000 births. The ppp field is an annual purchasing-power reference in international dollars. Missing happiness values remain null rather than being converted to zero.

Purchasing-power comparisons are not live foreign-exchange conversions. Monetary presentation in the interface can vary by the selected display region. Reference statistics may use different source years and can include estimates.


## Statistics and fictional outcomes

The age-specific mortality model adapts the reference project’s Gompertz–Makeham calibration. The TypeScript engine combines seeded progression, branching decisions, financial rules and fictional events. Many game mechanisms are simplified probability models rather than direct readings from a national dataset.

National averages do not describe every person or community. The game does not predict individual medical outcomes, wealth, immigration status or lifespan. It is designed for reflection and entertainment.


## Attribution and corrections

Consult the third-party notices for the full license and additional map-data attribution. Send suspected data or unit errors to contact@1in8bn.com with the country, indicator and a relevant public source.


## Sources

- [Dataset source at the recorded commit](https://github.com/rollroyces/born-somewhere/tree/c7cd3109456ceb22415cc9eba3f8f7cf73efa1b1)
- [Third-party notices and license](https://1in8bn.com/THIRD_PARTY_NOTICES.txt)
- [Natural Earth map data and terms](https://www.naturalearthdata.com/about/terms-of-use/)

## Reference library

- [About 1in8bn](https://1in8bn.com/reference/about/): What 1in8bn is: a free browser life simulator with 172 countries, choices, generations and keepsakes.
- [How to play 1in8bn](https://1in8bn.com/reference/how-to-play/): Start a life, choose a pace, make decisions, manage annual focus and save your progress in the free life simulator.
- [1in8bn frequently asked questions](https://1in8bn.com/reference/faq/): Answers about free play, countries, saving, languages, family, ICU, sharing, mobile support and embedding.
- [Family, adult children and later generations](https://1in8bn.com/reference/family-and-generations/): Understand family events, adult descendants, work, marriage, leaving home and migration in 1in8bn.
- [Health, illness and intensive care](https://1in8bn.com/reference/health-and-icu/): A gameplay guide to health events, treatment choices, intensive care and gentler play in 1in8bn.
- [Saving, sharing and free keepsakes](https://1in8bn.com/reference/saving-and-sharing/): Export and transfer saves, keep pixel artwork and life stories, and understand public memorials and iframe storage.
- [Data sources and simulation method](https://1in8bn.com/reference/data-and-method/): Dataset provenance, weighting, units, snapshot dates and limits of the 172-country life simulation.
- [Privacy and storage](https://1in8bn.com/reference/privacy/): How local saves, optional public memorials, cookieless analytics and anonymous player presence work.
- [Use of 1in8bn](https://1in8bn.com/reference/terms/): Age guidance, fictional simulation limits, community conduct, backups, embedding and third-party attribution.

- [Play 1in8bn](https://1in8bn.com/)
- [AI content index](https://1in8bn.com/llms.txt)