Main Factors: Fertility
Fertility rates have fallen in most Muslim-majority countries in recent decades. Yet they remain, on average, higher than in the rest of the developing world and considerably higher than in more-developed countries. This is one of the main reasons that the global Muslim population is projected to rise both in absolute numbers and in relative terms, as a share of all the people in the world.
Categories of Countries
For comparison purposes, this report provides demographic data on three types of countries:
As of 2010, there are 49 countries in which Muslims comprise more than 50% of the population. All Muslim majority countries are in less-developed regions of the world, with the exception of Albania and Kosovo, which are in Europe.
Non-Muslim-majority countries in less developed regions.
These countries make up the rest of the “developing world”; they include all the developing, non-Muslim majority countries in Africa, Asia-Pacific and Central and South America (including the Caribbean).
Non-Muslim-majority countries in more developed regions.
This category is often described as the “developed world”; it includes all countries in Europe and North America, plus Australia, New Zealand and Japan.
Taken as a whole, the world’s more-developed regions – including Europe, North America, Japan and Australia – have Total Fertility Rates (TFRs)3 below their replacement levels of about 2.1 children per woman, the minimum necessary to keep the population stable (absent other factors, such as immigration).4 Fertility rates in these more-developed nations are projected to rise slightly over the next 20 years but to remain, on average, well below replacement levels.
In non-Muslim-majority countries in less-developed regions – including all of Latin America, much of sub-Saharan Africa and parts of Asia – fertility rates have dropped in recent decades. They are projected to continue to drop, reaching or even falling below replacement levels in these developing countries as a whole in 2030-35.
In many Muslim-majority countries – including Indonesia, Iran, United Arab Emirates, Lebanon, Turkey and Tunisia – fertility rates also have dropped substantially. The average Total Fertility Rate for all 49 Muslim-majority countries has fallen from 4.3 children per woman in 1990-95 to an estimated 2.9 children in 2010-15. Over the next 20 years, fertility rates in these Muslim-majority countries as a whole are expected to continue to decline, though not quite as steeply, dropping to 2.6 children per woman in 2020-25 and 2.3 children in 2030-35 – approaching and possibly reaching replacement levels.
If current trends continue, fertility rates in Muslim-majority countries eventually may converge with fertility rates in other developing countries and in the world’s more-developed regions. But complete convergence is not projected to occur in the next two decades, as the trend lines in the above graph shows.
Moreover, high fertility rates in the past create a certain demographic momentum. Due to previously high fertility, large numbers of Muslim youth and young adults are now in (or entering) their prime childbearing years, all but ensuring that relatively rapid population growth will continue in the next two decades, even if the number of births per woman goes down. (For details, see the Age Structure section.)
Among the reasons for declining fertility rates in both Muslim-majority and non-Muslim-majority countries are economic development and improved living standards, higher levels of education, people waiting until they are older to get married, growing urbanization and more extensive use of birth control. (See the Related Factors section for a discussion of how these factors affect the global Muslim population.)
The overall trends in fertility, however, mask a considerable amount of variation from country to country. Among Muslim-majority countries, the highest Total Fertility Rates currently are found in Niger, Afghanistan and Somalia, where the average woman has more than six children during her lifetime. The lowest TFRs are in Iran (1.7) and Tunisia (1.8), which are well below replacement levels.
A final, cautionary note: The impact of religion on fertility rates is difficult to assess and remains a subject of debate. One should not assume, just because fertility tends to be higher in Muslim-majority countries than in other developing countries, that Islamic teachings are the reason. Cultural, social, economic, political, historical and other factors may play equal or greater roles.5 For example, many Muslims live in countries with higher-than-average rates of poverty, less-adequate health care, fewer educational opportunities and more-rural populations. All of these conditions are associated with higher fertility rates.
Islamic authorities in some countries, such as Afghanistan and Saudi Arabia, reinforce cultural norms that limit women’s autonomy by, for example, restricting their educational and career options or making it difficult for women to initiate a divorce. These restrictions may contribute to higher fertility because there is strong evidence that Muslim women, like other women around the world, tend to delay marriage – and consequently childbirth – as they attain higher levels of education. (See the discussion of education.) In Nigeria, for example, Muslim women generally have lower literacy levels and marry at younger ages; not surprisingly, Muslims also have higher fertility rates than non-Muslims in Nigeria. (For more details, see the Spotlight on Nigeria). However, recent studies suggest that in a number of other countries, including India and Malaysia, measures of women’s status cannot explain differences in fertility between Muslims and non-Muslims.6
Women in Muslim-majority countries tend to marry at much younger ages than women in more-developed countries, but there is little difference between the average age of marriage in Muslim-majority countries and in other less-developed countries. According to a Pew Forum analysis of U.N. data, women in Muslim-majority countries marry, on average, at 21.6 years, compared with 22.0 years in non-Muslim-majority, less-developed countries and 26.2 years in more-developed countries.7
Family planning is another arena in which the role of religion is not as simple as it might seem. Islamic edicts generally have supported the use of birth control, and a number of Muslim-majority countries (including Pakistan, Bangladesh, Indonesia, Iran, Turkey and Tunisia) have encouraged family planning programs. But many Muslims are either uneasy about contraceptives or do not have access to them, and women in Muslim-majority countries report using birth control at lower rates than women in other developing countries. In addition, many Muslim-majority countries forbid or strictly limit abortions. (See the discussion of contraception and family planning .)
There is also some evidence that across a variety of religious traditions, women who are more religious have higher fertility rates than less-religious women. This suggests that religiosity in general, rather than Islam in particular, may boost the number of children per woman.8 In short, Islamic beliefs may directly or indirectly influence the size of Muslim families, but religion does not operate in isolation from other forces; fertility rates appear to be driven by a complex mixture of cultural, social, economic, religious and other factors.
3 The standard measure of fertility in this report is the Total Fertility Rate, defined as the total number of children an average woman would have in her lifetime if fertility patterns did not change. The TFR is calculated by adding the birth rates among women in each age group in a particular country during a given period; in other words, it is a kind of snapshot of fertility patterns at one place and time. (return to text)
4 The replacement level varies depending on mortality rates and sex ratios at birth. In countries with a normal sex ratio at birth and relatively low infant and child mortality, a fertility rate of about 2.1 children per woman is sufficient to replenish the population. In some developing countries with high infant and child mortality, the replacement fertility rate is substantially greater than than 2.1 children per woman. Based on 2001 U.N. data, one study estimated the average replacement rate in Africa at 2.7 and the worldwide average at 2.3. See Thomas J. Espenshade, Juan Carlos Guzman and Charles F. Westoff, “The Surprising Global Variation in Replacement Fertility,” Population Research and Policy Review, Volume 22, Numbers 5-6, pages 575-583, December 2003. (return to text)
5 One study in West Africa, for example, found that in countries where Muslims are in the minority, they tend to have higher fertility than non-Muslims, while in countries in which Muslims are in the majority, they tend to have lower fertility than non- Muslims. “There is no single, coherent Muslim reproductive pattern: the real story is local,” the author asserts. See Jennifer Johnson-Hanks, “On the Politics and Practice of Muslim Fertility: Comparative Evidence from West Africa,” Medical Anthropology Quarterly, Volume 20, Number 1, pages 12-30, 2006. (return to text)
6 For instance, a study of Muslim and non-Muslim communities in India, Malaysia, Thailand and the Philippines found that the Muslim communities had more children per woman even though they did not score any lower on measures of women’s power or autonomy. See S. Philip Morgan, Sharon Stash, Herbert L. Smith and Karen Oppenheim Mason, “Muslim and Non-Muslim Differences in Female Autonomy and Fertility: Evidence from Four Asian Countries,” Population and Development Review, Volume 28, Number 3, pages 515-537, 2002. (return to text)
7 These figures are the average (mean) age of first marriage. They have been weighted by country populations so that more populous countries affect the average more than smaller countries. (return to text)
8 A 2007 study, for example, found that Muslim women in Europe who are highly religious are significantly more likely than less-religious Muslim women to have at least two children. See Charles F. Westoff and Tomas Frejka, “Religiousness and Fertility Among European Muslims,” Population and Development Review, Volume 33, Number 4, pages 785-809, December 2007. Other researchers have demonstrated the connection between fertility and religiosity in a variety of religious traditions. See, for example, Conrad Hackett, “Religion and Fertility in the United States: The Influence of Affiliation, Region, and Congregation,” Ph.D. dissertation, Department of Sociology and Office of Population Research, Princeton University, 2008; Sarah R. Hayford and S. Philip Morgan, “Religiosity and Fertility in the United States: The Role of Fertility Intentions,” Social Forces, Volume 86, Number 3, pages 1163-1188, March 2008; Evelyn Lehrer, “Religion as a Determinant of Marital Fertility,” Journal of Population Economics, Volume 9, Number 2, pages 173-196, 1996; and William D. Mosher, Linda B. Williams and David P. Johnson, “Religion and Fertility in the United States: New Patterns,” Demography, Volume 29, Number 2, pages 199-214, May 1992. (return to text)