Earth has a human population of over 8 billion as of 2024, with an overall population density of 50 people per km2 (130 per sq. mile). Nearly 60% of the world's population lives in Asia, with almost 2.8 billion in the countries of China and India combined. The percentage shares of China, India and rest of South Asia of the world population have remained at similar levels for the last few thousand years of recorded history.[1][2] The world's literacy rate has increased dramatically in the last 40 years, from 66.7% in 1979 to 86.3% today.[3] Lower literacy levels are mostly attributable to poverty.[citation needed] Lower literacy rates are found mostly in South Asia and Sub-Saharan Africa.[4]
The world's population is predominantly urban and suburban,[5] and there has been significant migration toward cities and urban centres. The urban population jumped from 29% in 1950 to 55.3% in 2018.[6][7] Interpolating from the United Nations prediction that the world will be 51.3 percent urban by 2010, Ron Wimberley, Libby Morris and Gregory Fulkerson estimated 23 May 2007 would have been the first time the urban population was more populous than the rural population in history.[8]India and China are the most populous countries,[9] as the birth rate has consistently dropped in wealthy countries and until recently remained high in poorer countries. Tokyo is the largest urban agglomeration in the world.[7]
As of 2021, the total fertility rate of the world is estimated at 2.32[10] children per woman, which is slightly below the global average for the replacement fertility rate of approximately 2.33 (as of 2003),[11] which would mean the world's population is declining. However, world population growth is unevenly distributed, with the total fertility rate ranging from one of the world's lowest 0.83 in Singapore, to the highest, 6.49 in Niger.[12] The United Nations estimated an annual population increase of 1.14% for the year of 2000.[13]
The current world population growth is approximately 1.09%.[7] People under 15 years of age made up over a quarter of the world population (25.18%), and people age 65 and over made up nearly ten percent (9.69%) in 2021.[7]
The world population more than tripled during the 20th century from about 1.65 billion in 1900 to 5.97 billion in 1999.[14][15][16] It reached the 2 billion mark in 1927, the 3 billion mark in 1960, 4 billion in 1974, and 5 billion in 1987.[17] The overall population of the world is approximately 8 billion as of November 2022. Currently, population growth is fastest among low wealth, least developed countries.[18] The UN projects a world population of 9.15 billion in 2050, a 32.7% increase from 6.89 billion in 2010.[14]
History
Comparison of humans living today with all previous generations
Historical migration of human populations begins with the movement of Homo erectus out of Africa across Eurasia about a million years ago. Homo sapiens appear to have occupied all of Africa about 300,000 years ago, moved out of Africa 50,000 – 60,000 years ago, and had spread across Australia, Asia and Europe by 30,000 years BC. Migration to the Americas took place 20,000 to 15,000 years ago, and by 2,000 years ago, most of the Pacific Islands were colonized.
Since 1800, the human population has increased from one billion[19] to over eight billion.[20] In 2004, some 2.5 billion out of 6.3 billion people (39.7%) lived in urban areas. In February 2008, the U.N. estimated that half the world's population would live in urban areas by the end of the year.[21] Problems for humans living in cities include various forms of pollution and crime,[22] especially in inner city and suburban slums. Both overall population numbers and the proportion residing in cities are expected to increase significantly in the coming decades.[23]
World Population, AD 1–1998 (in thousands)
Source: Maddison and others. (University of Groningen).[24]
Shares of world population, AD 1–1998 (% of world total)
Source: Maddison and others. (University of Groningen).[24]
Year
1
1000
1500
1600
1700
1820
1870
1913
1950
1973
1998
Western Europe
10.7
9.5
13.1
13.3
13.5
12.8
14.8
14.6
12.1
9.2
6.6
Eastern Europe (excluding USSR countries)
2.1
2.4
3.1
3.0
3.1
3.5
4.1
4.4
3.5
2.8
2.0
Former USSR
1.7
2.6
3.9
3.7
4.4
5.3
7.0
8.7
7.1
6.4
4.9
Total Europe (including USSR countries)
14.5
14.5
20.1
20.0
21.0
21.6
25.9
27.7
22.7
18.4
13.5
United States
0.3
0.5
0.5
0.3
0.2
1.0
3.2
5.4
6.0
5.4
4.6
Other Western Offshoots
0.2
0.2
0.2
0.1
0.1
0.1
0.5
0.8
0.9
1.0
0.9
Total Western Offshoots
0.5
0.7
0.6
0.4
0.3
1.1
3.6
6.2
7.0
6.4
5.5
Mexico
1.0
1.7
1.7
0.4
0.7
0.6
0.7
0.8
1.1
1.5
1.7
Other Latin America
1.5
2.6
2.3
1.1
1.3
1.4
2.4
3.7
5.4
6.4
6.9
Total Latin America
2.4
4.2
4.0
1.5
2.0
2.0
3.1
4.5
6.6
7.9
8.6
Japan
1.3
2.8
3.5
3.3
4.5
3.0
2.7
2.9
3.3
2.8
2.1
China
25.8
22.0
23.5
28.8
22.9
36.6
28.2
24.4
21.7
22.5
21.0
India
32.5
28.0
25.1
24.3
27.3
20.1
19.9
17.0
14.2
14.8
16.5
Other Asia
15.9
15.4
12.7
11.7
11.9
8.6
9.4
10.3
15.5
17.3
19.8
Total Asia (excluding Japan)
74.2
65.4
61.3
64.8
62.1
65.3
57.5
51.7
51.4
54.7
57.4
Africa
7.1
12.3
10.5
9.9
10.1
7.1
7.1
7.0
9.0
9.9
12.9
World
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
Historical vital statistics
The following estimates of global trends in various demographic indicators from 1950 to 2021 are from UN DESA's World Population Prospects 2022. In July 2022, UN DESA published its 2022 World Population Prospects, a biennially-updated database where key demographic indicators are estimated and projected worldwide and on the country and regional level.[26]
The world's population is over 8 billion[38] and Earth's total surface area (including land and water) is 510 million square kilometres (197 million square miles).[39] Therefore, the worldwide human population density is 8 billion ÷ 510 million km2 (197 million sq mi) = 15.7 people/km2 (41 people/sq mi). If only the Earth's land area of 150 million km2 (58 million sq mi) is taken into account, then human population density increases to 53.3 people/km2 (138 people/sq mi).[40][41]
Several of the most densely populated territories in the world are city-states, microstates or dependencies.[42][43] These territories share a relatively small area and a high urbanization level, with an economically specialized city population drawing also on rural resources outside the area, illustrating the difference between high population density and overpopulation.
The table below lists religions classified by philosophy; however, religious philosophy is not always the determining factor in local practice. Please note that this table includes heterodox movements as adherents to their larger philosophical category, although this may be disputed by others within that category. For example, Cao Đài is listed because it claims to be a separate category from Buddhism, while Hòa Hảo is not, even though they are similar new religious movements.
The population numbers below are computed by a combination of census reports, random surveys (in countries where religion data is not collected in census, for example United States or France), and self-reported attendance numbers, but results can vary widely depending on the way questions are phrased, the definitions of religion used and the bias of the agencies or organizations conducting the survey. Informal or unorganized religions are especially difficult to count. Some organizations may wildly inflate their numbers.
West Asia, Northern Africa, Central Asia, Indian Subcontinent, Western Africa, Maritime Southeast Asia with large population centers existing in Eastern Africa, Balkan Peninsula, Russia and China.[49]
Noted for being dispersed worldwide[59][60] but the top ten populations (amounting to about 65% of the world's Baháʼí Faith adherents) are (in order of size of community) India, United States, Kenya, Vietnam, DR of the Congo, Philippines, Iran, Zambia, South Africa, Bolivia[61]
Since the late 19th century, the demographics of religion have changed a great deal. Some countries with a historically large Christian population have experienced a significant decline in the numbers of professed active Christians: see demographics of atheism. Symptoms of the decline in active participation in Christian religious life include declining recruitment for the priesthood and monastic life, as well as diminishing attendance at church. On the other hand, since the 19th century, large areas of sub-Saharan Africa have been converted to Christianity, and this area of the world has the highest population growth rate. In the realm of Western civilization, there has been an increase in the number of people who identify themselves as secular humanists. Despite the decline, Christianity remains the dominant religion in the Western world, where 70% of the population is Christian.[69] In many countries, such as the People's Republic of China, communist governments have discouraged religion, making it difficult to count the actual number of believers. However, after the collapse of communism in numerous countries of Eastern Europe and the former Soviet Union, religious life has been experiencing resurgence there, in the form of traditional Eastern Christianity.[70] While, Islam however has gained considerably in the Soviet Unions former republics in Central Asia.
The annual growth in the world population over the same period is 1.41%.
Studies conducted by the Pew Research Center have found that, generally, poorer nations had a larger proportion of citizens who found religion to be very important than richer nations, with the exceptions of the United States[76] and Kuwait.[77]
Marriage
The average age of marriage varies greatly from country to country and has varied through time. Women tend to marry earlier than men and currently varies from 17.6 for women in Niger, to 32.4 for women in Denmark while men range from 22.6 in Mozambique to 35.1 in Sweden.[78]
In 2021, 13.3 million babies, or about 10 per cent of the total worldwide, were born to mothers under 20 years old.[27]
Age structure
Population pyramid of the World from 1950 to 2100 by the UN
65 years and over: 9.7% (male 337,244,947/female 415,884,753) (2021 est.)[7]
Median Age – 31 years (male: 30.3 years, female: 31.8 years, 2021 est.)
According to a report by the Global Social Change Research Project, worldwide, the percent of the population age 0–14 declined from 34% in 1950 to 27% in 2010. The elderly population (60+) increased during the same period from 8% to 11%.[80]
Median age by country as of 2017. A youth bulge is evident for Africa, and to a lesser extent for West Asia, South Asia, Southeast Asia and parts of the Americas.
Growth rate of world population (1950–2010) The sharp decline in world population growth in the early 1960s caused primarily by the Great Chinese Famine
Globally, the growth rate of the human population has been declining since peaking in 1962 and 1963 at 2.20% per annum. In 2009, the estimated annual growth rate was 1.1%.[82] The CIA World Factbook gives the world annual birthrate, mortality rate, and growth rate as 1.915%, 0.812%, and 1.092% respectively[83] The last one hundred years have seen a rapid increase in population due to medical advances and massive increase in agricultural productivity[84] made possible by the Green Revolution.[85][86][87]
2010–2015 net population increase rate, per 1000 people
The actual annual growth in the number of humans fell from its peak of 88.0 million in 1989, to a low of 73.9 million in 2003, after which it rose again to 75.2 million in 2006. Since then, annual growth has declined. In 2009, the human population increased by 74.6 million, which is projected to fall steadily to about 41 million per annum in 2050, at which time the population will have increased to about 9.2 billion.[82] Each region of the globe has seen great reductions in growth rate in recent decades, though growth rates remain above 2% in some countries of the Middle East and Sub-Saharan Africa, and also in South Asia, Southeast Asia, and Latin America.[88]
Population in the world increased from 1990 to 2008 with 1,423 billion and 27% growth. Measured by persons, the increase was highest in India (290 million) and China (192 million). Population growth was highest in Qatar (174%) and United Arab Emirates (140%).[91]
In 2022 the world population reached the 8 billion. The latest projections by the United Nations suggest that the global population could grow to around 8.5 billion in 2030, 9.7 billion in 2050 and 10.4 billion in 2100.[27]
In 2021, most births worldwide occurred in two regions: sub-Saharan Africa
(29 per cent of global births), the region with the highest fertility level, Central and Southern Asia (28 per cent of global births) and Eastern and South-Eastern Asia (18 per cent).[92]
Birth count
Data required on total number of births per year, and distribution by country.
As of 2009, the average birth rate (unclear whether this is the weighted average rate per country [with each country getting a weight of 1], or the unweighted average of the entire world population) for the whole world is 19.95 per year per 1000 total population, a 0.48% decline from 2003's world birth rate of 20.43 per 1000 total population.
World historical and predicted crude birth rates (1950–2050) UN, medium variant, 2008 rev.[93]
Years
CBR
Years
CBR
1950–1955
37.2
2000–2005
21.2
1955–1960
35.3
2005–2010
20.3
1960–1965
34.9
2010–2015
19.4
1965–1970
33.4
2015–2020
18.2
1970–1975
30.8
2020–2025
16.9
1975–1980
28.4
2025–2030
15.8
1980–1985
27.9
2030–2035
15.0
1985–1990
27.3
2035–2040
14.5
1990–1995
24.7
2040–2045
14.0
1995–2000
22.5
2045–2050
13.4
According to the CIA – The World Factbook, the country with the highest birth rate currently is Niger at 51.26 births per 1000 people. The country with the lowest birth rate is Japan at 7.64 births per 1000 people. Hong Kong, a Special Administrative Region of China, is at 7.42 births per 1000 people. As compared to the 1950s, birth rate was at 36 births per 1000 in the 1950s,[94] birth rate has declined by 16 births per 1000 people. In July 2011, the U.S. National Institutes of Health announced that the adolescent birth rate continues to decline.[95]
Birth rates vary even within the same geographic areas. In Europe, as of July 2011, Ireland's birth rate is 16.5 percent, which is 3.5 percent higher than the next-ranked country, the UK. France has a birth rate of 12.8 per cent while Sweden is at 12.3 percent.[96] In July 2011, the UK's Office for National Statistics (ONS) announced a 2.4% increase in live births in the UK in 2010 alone.[97] This is the highest birth rate in the UK in 40 years.[97] By contrast, the birth rate in Germany is only 8.3 per 1,000, which is so low that both the UK and France, which have significantly smaller populations, produced more births in 2010.[98] Birth rates also vary within the same geographic area, based on different demographic groups. For example, in April 2011, the U.S. CDC announced that the birth rate for women over the age of 40 in the U.S. rose between 2007 and 2009, while it fell among every other age group during the same time span.[99] In August 2011, Taiwan's government announced that its birth rate declined in the previous year, despite the fact that it implemented a host of approaches to encourage its citizens to have babies.[100]
Birth rates ranging from 10 to 20 births per 1000 are considered low, while rates from 40 to 50 births per 1000 are considered high. There are problems associated with both an extremely high birth rate and an extremely low birth rate. High birth rates can cause stress on the government welfare and family programs to support a youthful population. Additional problems faced by a country with a high birth rate include educating a growing number of children, creating jobs for these children when they enter the workforce, and dealing with the environmental effects that a large population can produce. Low birth rates can put stress on the government to provide adequate senior welfare systems and also the stress on families to support the elders themselves. There will be less children or working age population to support the constantly growing aging population.
The ten countries with the highest and lowest crude birth rate, according to the 2018 and 2022 CIA World Factbook estimates, are:[101]
Causes of death vary greatly between first and third world countries.
According to Jean Ziegler (the United Nations Special Rapporteur on the Right to Food for 2000 to March 2008), mortality due to malnutrition accounted for 58% of the total mortality in 2006: "In the world, approximately 62 millions people, all causes of death combined, die each year. In 2006, more than 36 millions died of hunger or diseases due to deficiencies in micronutrients".[104]
Of the roughly 150,000 people who died each day across the globe, about two-thirds—100,000 per day—died of age-related causes in 2001, according to an article which counts all deaths "due to causes that kill hardly anyone under the age of 40" as age-related.[105][better source needed] In industrialized nations, the proportion was even higher according to that article, reaching 90%.[105]
The Total fertility rate is the average number of children born per mother. In 2021, fertility levels high were found in sub-Saharan Africa (4.6 births per woman), Oceania excluding Australia and New Zealand (3.1), Northern Africa and Western Asia
(2.8), and Central and Southern Asia (2.3).[27]
There is an inverse correlation between income and fertility, wherein developed countries usually have a much lower fertility rate. Various fertility factors may be involved, such as education and urbanization. Mortality rates are low, birth control is understood and easily accessible, and costs are often deemed very high because of education, clothing, feeding, and social amenities. With wealth, contraception becomes affordable. However, in countries like Iran where contraception was made artificially affordable before the economy accelerated, birth rate also rapidly declined. Further, longer periods of time spent getting higher education often mean women have children later in life.[106] Female labor participation rate also has substantial negative impact on fertility. However, this effect is neutralized among Nordic or liberalist countries.[107][further explanation needed]
In undeveloped countries on the other hand, families desire children for their labour and as caregivers for their parents in old age. Fertility rates are also higher due to the lack of access to contraceptives, generally lower levels of female education, patriarchal culture and lower rates of female employment in industry.
The average number of hospital beds per 1,000 population is 2.94. It is highest in Switzerland (18.3) and lowest in Mexico (1.1)[110]
96% of the urban population has access to improved drinking water, while only 78% of rural inhabitants have improved drinking water. A total average of 87% of urban and rural have access to improved drinking water.
4% of the urban population does not have access to improved drinking water, leaving 22% of rural people without improved drinking water with a total world population of 13% not having access to drinking water.
76% of the urban population has access to sanitation facilities, while only 45% of the rural population has access. A total world average of 39% do not have access to sanitation facilities.
As of 2009, there are an estimated 33.3 million people living with HIV/AIDS, which is approximately 0.8% of the world population, and there have been an estimated 1.8 million deaths attributed to HIV/AIDS.
As of 2010, 925 million people are undernourished.[111]
World historical and predicted total life expectancy at birth (1950–2050) UN, 2017 rev.[112]
Years
LEB
Years
LEB
1950–1955
47.9
2000–2005
67.2
1955–1960
49.3
2005–2010
69.1
1960–1965
51.2
2010–2015
70.8
1965–1970
55.5
2015–2020
72.0
1970–1975
58.1
2020–2025
73.0
1975–1980
60.3
2025–2030
73.8
1980–1985
62.1
2030–2035
74.7
1985–1990
63.7
2035–2040
75.5
1990–1995
64.6
2040–2045
76.2
1995–2000
65.7
2045–2050
77.0
Sex ratio
Map indicating the human sex ratio by country.
Countries with more females than males.
Countries with similar number of males and females.
Countries with more males than females.
No data
The value for the entire world population is 1.02 males/female,[113] with 1.07 at birth, 1.06 for those under 15, 1.02 for those between 15 and 64, and 0.78 for those over 65.
The Northern Mariana Islands have the highest female ratio with 0.77 males per female. Qatar has the highest male ratio, with 2.87 males/female. For the group aged below 15, Sierra Leone has the highest female ratio with 0.96 males/female, and Georgia and China are tied for the highest male ratio with 1.13 males/female (according to the 2006 CIA World Factbook).
The "First World" G7 members all have a gender ratio in the range of 0.95–0.98 for the total population, of 1.05–1.07 at birth, of 1.05–1.06 for the group below 15, of 1.00–1.04 for the group aged 15–64, and of 0.70–0.75 for those over 65.
Countries on the Arabian Peninsula tend to have a "natural" ratio of about 1.05 at birth but a very high ratio of males for those over 65 (Saudi Arabia 1.13, United Arab Emirates 2.73, Qatar 2.84), indicating either an above-average mortality rate for females or a below-average mortality for males, or, more likely in this case, a large population of aging male guest workers. Conversely, countries of Eastern Europe (the Baltic states, Belarus, Ukraine, Russia) tend to have a "normal" ratio at birth but a very low ratio of males among those over 65 (Russia 0.46, Latvia 0.48, Ukraine 0.52); similarly, Armenia has a far above average male ratio at birth (1.17), and a below-average male ratio above 65 (0.67). This effect may be caused by emigration and higher male mortality as result of higher post-Soviet era deaths; it may also be related to the enormous (by western standards) rate of alcoholism in the former Soviet states. Another possible contributory factor is an aging population, with a higher than normal proportion of relatively elderly people: we recall that due to higher differential mortality rates the ratio of males to females reduces for each year of age.
Unemployment rate
8.7% (2010 est.)
8.2% (2009 est.)
note: 30% combined unemployment and underemployment in many non-industrialized countries; developed countries typically 4%–12% unemployment (2007 est.)
Languages
Primary language families of the world (and in some cases geographic groups of families). For greater detail, see Distribution of languages in the world.
Worldwide, English is used widely as a lingua franca and can be seen to be the dominant language at this time. The world's largest language by native speakers is Mandarin Chinese which is a first language of around 960 million people, or 12.44% of the population, predominantly in Greater China. Spanish is spoken by around 330 to 400 million people, predominantly in the Americas and Spain. Hindustani (Hindi-Urdu) is spoken by about 370 to 420 million speakers, mostly in India and Pakistan.
World map of countries shaded according to the literacy rate for all people aged 15 and over, as of 2015.[114]
Total population: 83.7% over the age of 15 can read and write, 88.3% male and 79.2% female[citation needed]
note: over two-thirds of the world's 793 million illiterate adults are found in only eight countries (Bangladesh, China, Egypt, Ethiopia, India, Indonesia, Nigeria, and Pakistan); of all the illiterate adults in the world, two-thirds are women; extremely low literacy rates are concentrated in three regions, the Arab states, South and West Asia, and Sub-Saharan Africa, where around one-third of the men and half of all women are illiterate (2005–09 est.)[citation needed]
As of 2008, the school life expectancy (primary to tertiary education) for a man or woman is 11 years.[citation needed]
^The area figures are taken from individual national censuses according to the criteria and statistical concepts noted in the World Urbanization Prospects.
^As defined by the Statistics Bureau of Japan; refers to Kanto major metropolitan area (M.M.A.)
^The population of the city is composed of population in all City Districts meeting the criteria such as "contiguous built-up area", being the location of the local government, being a Street or Having a Resident Committee.
^Based on a definition of urban agglomeration that is not restricted to state boundaries.
^The Greater Mumbai urban agglomeration is defined by the municipal corporations of Greater Mumbai, Kalyan-Dombivali, Navi Mumbai, Thane and Ulhasnagar, plus the municipal councils of Ambarnath, Badlapur and Mira-Bhayandar. Not to be confused with the Mumbai Metropolitan Region, which includes some additional urban and rural units.
^ abThe number of people who consider themselves party to a "folk tradition" is impossible to determine.
^Figures for the population of Jains differ from just over six million to twelve million due to difficulties of Jain identity, with Jains in some areas counted as a Hindu sect. Many Jains do not return Jainism as their religion on census forms for various reasons such as certain Jain castes considering themselves both Hindu and Jain. Following a major advertising campaign urging Jains to register as such, the 1981 Census of India returned 3.19 million Jains. This was estimated at the time to still be half the true number. The 2001 Census of India had 8.4 million Jains.
^Historically, the Baháʼí Faith arose in 19th century Persia, in the context of Shia Islam, and thus may be classed on this basis as a divergent strand of Islam, placing it in the Abrahamic tradition. However, the Baháʼí Faith considers itself an independent religious tradition, which draws from Islam but also other traditions. The Baháʼí Faith may also be classed as a new religious movement, due to its comparatively recent origin, or may be considered sufficiently old and established for such classification to not be applicable.
^This list includes only independent countries, not regions.
^This list includes only independent countries, not regions.
^This list includes only independent countries, not regions.
^Since the Mongolic and Tungusic language families have only a relatively small number of speakers, the majority of the Altaic percentage represents speakers of Turkic languages.
^Espenshade TJ, Guzman JC, Westoff CF (2003). "The surprising global variation in replacement fertility". Population Research and Policy Review. 22 (5/6): 575. doi:10.1023/B:POPU.0000020882.29684.8e. S2CID10798893., Introduction and Table 1, p. 580
^Department of Economic and Social Affairs Population Division (2009). "World Population Prospects, Table A.1"(PDF). 2008 revision. United Nations. Retrieved 12 March 2009. ((cite journal)): Cite journal requires |journal= (help)
^The Monaco government uses a smaller surface area figure resulting in a population density of 18,078 per km2
^Fischer-Schreiber, Ingrid, et al. The Encyclopedia of Eastern Philosophy & Religion: Buddhism, Hinduism, Taoism, Zen. Shambhala: Boston (English: pub. 1994; orig. German: 1986); pg. 50.
^Encyclopædia Britannica (2002). "Worldwide Adherents of All Religions by Six Continental Areas, Mid-2002". Encyclopædia Britannica. Encyclopædia Britannica. ISBN978-0-85229-555-7.
^MacEoin, Denis (2000). "Baha'i Faith". In Hinnells, John R. (ed.). The New Penguin Handbook of Living Religions: Second Edition. Penguin. ISBN978-0-14-051480-3.
^Self-reported figures from 1999; North Korea only (South Korean followers are minimal according to self-reported figures). In The A to Z of New Religious Movements by George D. Chryssides. ISBN978-0-8108-5588-5
^Encyclopedia of the Modern Middle East and North Africa (Detroit: Thomson Gale, 2004) p. 82
^Clarke, Peter B. (editor), The Religions of the World: Understanding the Living Faiths, Marshall Editions Limited: USA (1993); pg. 208. "Sekai Kyuseikyo has about one million members, a growing number of them in the west and the third world, especially Brazil and Thailand. "
^Leonard E. Barrett. The Rastafarians: Sounds of Cultural Dissonance. Beacon Press, 1988. p. viii.
^The results have been studied and found "highly correlated with other sources of data", but "consistently gave a higher estimate for percent Christian in comparison to other cross-national data sets." Hsu, Becky; Reynolds, Amy; Hackett, Conrad; Gibbon, James (9 July 2008). "Estimating the Religious Composition of All Nations"(PDF). Journal for the Scientific Study of Religion. 47 (4): 678–693. doi:10.1111/j.1468-5906.2008.00435.x. Archived from the original(PDF) on 26 March 2010.
