Can I use some or all of The World Factbook for my Web site (book, research project, homework, etc.)?
The World Factbook is in the public domain and may be used freely by anyone at anytime without seeking permission. However, US Code (Section 403m) prohibits use of the CIA seal in a manner which implies that the CIA approved, endorsed, or authorized such use. For any questions about your intended use, you should consult with legal counsel. Further information on use of The World Factbook is described on the Contributors and Copyright Information page. As a courtesy, please cite The World Factbook when used.
Why are there discrepancies between The World Factbook's demographic statistics and other sources?
Although estimates and projections start with the same basic data from censuses, surveys, and registration systems, final estimates and projections can differ as a result of factors including data availability, assessment, and methods and protocols.
Data availability Researchers may obtain specific country data at different times. Estimates or projections developed before the results of a census have been released will not be as accurate as those that take into account new census results.
Assessment Researchers can differ in their assessment of data quality and in their estimates based on the available country data. They often need to adjust their estimates due to such factors as undercounting in a census or underregistration of births or deaths.
Methods and protocols Differences in methods and protocols can shape the way estimates and projections are made of fertility, mortality, and international migration, and how these data are integrated with the population data. For example, the US Census Bureau uses a model that projects the population ahead by single years of age, a single year at a time (population statistics used in the Factbook are based on this model), whereas the United Nations model projects five-year age groups forward, five years at a time.
Why doesn't The World Factbook include information on states, departments, provinces, etc., for each country?
The World Factbook provides national-level information on countries, territories, and dependencies, but not subnational administrative units within a country. A comprehensive encyclopedia might be a source for state/province-level information.
Is it possible to access older editions of The World Factbook to do comparative research and trend analysis?