January 15, 2011

The Future of the Global Muslim Population

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Population estimates are rounded to thousands. Percentages are calculated from unrounded numbers.

* These figures are projections. The projections presented in this report are the medium figures in a range of three scenarios – high, medium and low – generated from models commonly used by demographers around the world to forecast changes in population size and composition. The models follow what is known as the cohort-component method, which starts with a baseline population (in this case, the current number of Muslims in each country) divided into groups, or cohorts, by age and sex. Each cohort is projected into the future by adding likely gains – new births and immigrants – and subtracting likely losses – deaths and emigrants. These calculations were made by the Pew Forum’s demographers, who collaborated with researchers at the International Institute for Applied Systems Analysis (IIASA) in Austria on the projections for the United States and European countries. (From the Executive Summary of The Future of the Global Muslim Population. For more details, see the Full Report and Methodology.)

A note on historical data: This interactive feature provides estimates for 1990 and 2000 based on national censuses, demographic and health surveys, and general population surveys and studies available for those years. However, the sources for 1990 appear to have substantially understated the actual number of Muslims in Angola, Cyprus, France, Gabon, Mozambique and Ukraine, while substantially overstating the number in Colombia, Georgia, Mongolia, Panama, Taiwan and Vietnam. The 2000 estimates appear to have undercounted Muslims in Cyprus, France, Guatemala, Hungary, Slovakia and Vietnam, while overcounting the number in Laos, Lesotho and Taiwan. These likely undercounts and overcounts should be taken into consideration when looking at growth rates, particularly in the affected countries. The number of Muslims in Vietnam, for example, may not have dropped from 1990 to 2000 and then climbed rapidly from 2000 to 2010; rather, the 1990 figure was probably too high an estimate, and the 2000 figure may have been too low. These problems in the historical data are a reminder that new censuses and surveys sometimes contradict older ones. This report and interactive feature are based on the best data available as of mid-2010.

A note on the Asia-Pacific map: Arrows next to some island countries indicate that their correct geographic locations are outside the borders of the map.