
Income and
fertility
Fertility in colloquial terms refers the ability to have offspring. In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to reproduce, which is termed fecundity. The fertility rate ...
is the association between monetary gain on one hand, and the tendency to produce offspring on the other. There is generally an inverse correlation between income and the
total fertility rate
The total fertility rate (TFR) of a population is the average number of children that are born to a woman over her lifetime, if they were to experience the exact current age-specific fertility rates (ASFRs) through their lifetime, and they were t ...
within and between nations. The higher the degree of education and GDP per capita of a human population, subpopulation or
social stratum
Social stratification refers to a society's categorization of its people into groups based on socioeconomic factors like wealth, income, race, education, ethnicity, gender, occupation, social status, or derived power (social and political). It ...
, the fewer children are born in any developed country. In a 1974 United Nations population conference in Bucharest,
Karan Singh, a former minister of population in India, illustrated this trend by stating "Development is the best
contraceptive
Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth control only be ...
." In 2015, this thesis was supported by Vogl, T.S., who concluded that increasing the cumulative educational attainment of a generation of parents was by far the most important predictor of the inverse correlation between income and fertility based on a sample of 48 developing countries.
Generally a developed country has a lower fertility rate while a less economically developed country has a higher fertility rate. For example the total fertility rate for Japan, a developed country with per capita GDP of US$32,600 in 2009, was 1.22 children born per woman. But total fertility rate in Ethiopia, with a per capita GDP of $900 in 2009, was 6.17 children born per woman.
Demographic–economic paradox
Herwig Birg has called the inverse relationship between income and fertility a "demo-economic paradox".
Evolutionary biology
Evolutionary biology is the subfield of biology that studies the evolutionary processes such as natural selection, common descent, and speciation that produced the diversity of life on Earth. In the 1930s, the discipline of evolutionary biolo ...
predicts that more successful individuals (and by analogy countries) should seek to develop optimum conditions for their life and reproduction. However, in the last half of the 20th century it has become clear that the economic success of developed countries is being counterbalanced by a
demographic
Demography () is the statistics, statistical study of human populations: their size, composition (e.g., ethnic group, age), and how they change through the interplay of fertility (births), mortality (deaths), and migration.
Demographic analy ...
failure, a
sub-replacement fertility
Sub-replacement fertility is a total fertility rate (TFR) that (if sustained) leads to each new generation being less populous than the older, previous one in a given area. The United Nations Population Division defines sub-replacement fertilit ...
that may prove destructive for their future economies and societies.
Causes and related factors
It is hypothesized that the observed trend in many countries of having fewer children has come about as a response to increased
life expectancy
Human life expectancy is a statistical measure of the estimate of the average remaining years of life at a given age. The most commonly used measure is ''life expectancy at birth'' (LEB, or in demographic notation ''e''0, where '' ...
, reduced
child mortality
Child mortality is the death of children under the age of five. The child mortality rate (also under-five mortality rate) refers to the probability of dying between birth and exactly five years of age expressed per 1,000 live births.
It encompa ...
, improved female literacy and independence, and urbanization that all result from increased GDP per capita,
consistent with the
demographic transition model
Demography () is the statistical study of human populations: their size, composition (e.g., ethnic group, age), and how they change through the interplay of fertility (births), mortality (deaths), and migration.
Demographic analysis examine ...
. The increase in GDP in Eastern Europe after 1990 has been correlated with childbearing postponement and a sharp decline in fertility.
In developed countries where birth control is the norm, increased income is likewise associated with decreased fertility. Theories behind this include:
* People earning more have a higher
opportunity cost
In microeconomic theory, the opportunity cost of a choice is the value of the best alternative forgone where, given limited resources, a choice needs to be made between several mutually exclusive alternatives. Assuming the best choice is made, ...
if they focus on childbirth and parenting rather than their continued career.
* Women who can economically sustain themselves have less incentive to become married.
[
* Higher-income parents value quality over quantity and so spend their resources on fewer children.]
From the 1970s to the late 2000s, parental spending increased. At the same time, investment in male and female children changed substantially: in the early 1970s, households with only female children spent significantly less than parents in households with only male children, but by the 1990s spending had equalized, and by the late 2000s girls gained an advantage. In addition, before the 1990s, parents spent the most on children in their teens. After the 1990s, however, the highest spending was on children under age 6 and in their mid-20s. The motives for the increase in parental investment in children, both in terms of financial and time investment are diverse. Anne H. Gauthier and Petra W. de Jong evidence that for middle-income parents in Canada and the US these motives are the goal of providing children with human
Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...
and social capital
Social capital is a concept used in sociology and economics to define networks of relationships which are productive towards advancing the goals of individuals and groups.
It involves the effective functioning of social groups through interper ...
to improve their future labor market prospects, the pressures on parents to conform to new societal standards of good and intensive parenting, and the experience of parenting as part of self-development. Philip H. Brown analyzed parenting patterns in rural China and found that more educated parents make greater educational investments in both goods
In economics, goods are anything that is good, usually in the sense that it provides welfare or utility to someone. Alan V. Deardorff, 2006. ''Terms Of Trade: Glossary of International Economics'', World Scientific. Online version: Deardorffs ...
and time with the objective of higher returns to education for children.
Religion sometimes modifies the effect; higher income is associated with slightly increased fertility among Catholic
The Catholic Church (), also known as the Roman Catholic Church, is the List of Christian denominations by number of members, largest Christian church, with 1.27 to 1.41 billion baptized Catholics Catholic Church by country, worldwid ...
couples but is associated with slightly decreased fertility among Protestant
Protestantism is a branch of Christianity that emphasizes Justification (theology), justification of sinners Sola fide, through faith alone, the teaching that Salvation in Christianity, salvation comes by unmerited Grace in Christianity, divin ...
couples.[Page 238]
Scholars also find a link between the European Marriage Pattern, which is marked by comparatively late marriage and consequently decreased fertility
Fertility in colloquial terms refers the ability to have offspring. In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to reproduce, which is termed fecundity. The fertility rate ...
, and the economic growth. This demographic pattern is considered to influence the stock of human capital
Human capital or human assets is a concept used by economists to designate personal attributes considered useful in the production process. It encompasses employee knowledge, skills, know-how, good health, and education. Human capital has a subs ...
and thus to contribute to Western Europe's development advantage.
Ansley Coale's ''Three Preconditions for Decline in Fertility'' asserts that increases in a society's income may increase its fertility, but only if three preconditions are met, summarized as "ready, willing and able". People will respond to economic and social opportunities that make it advantageous to limit fertility, considering the economic and psychosocial costs such as the cost of birth control
Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth control only be ...
or abortion
Abortion is the early termination of a pregnancy by removal or expulsion of an embryo or fetus. Abortions that occur without intervention are known as miscarriages or "spontaneous abortions", and occur in roughly 30–40% of all pregnan ...
s.
The review of the application of the traditional micro-economic
Microeconomics is a branch of economics that studies the behavior of individuals and firms in making decisions regarding the allocation of scarce resources and the interactions among these individuals and firms. Microeconomics focuses on the ...
models to the analysis of fertility
Fertility in colloquial terms refers the ability to have offspring. In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to reproduce, which is termed fecundity. The fertility rate ...
decisions shows that, from economic point of view, children either are considered to yield utility
In economics, utility is a measure of a certain person's satisfaction from a certain state of the world. Over time, the term has been used with at least two meanings.
* In a normative context, utility refers to a goal or objective that we wish ...
directly, or are not desired for themselves, but are by-product
A by-product or byproduct is a secondary product derived from a production process, manufacturing process or chemical reaction; it is not the primary product or service being produced.
A by-product can be useful and marketable or it can be cons ...
s of sexual activity or investment goods.
Consequences
Across countries there is a strong negative correlation between gross domestic product and fertility
Fertility in colloquial terms refers the ability to have offspring. In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to reproduce, which is termed fecundity. The fertility rate ...
, and ultimately it is proven that a strong negative correlation exists between household income and fertility.
A reduction in fertility can lead to an aging population, which can lead to a variety of problems. See for example the demographics of Japan
The demographics of Japan include birth and death rates, age distribution, population density, ethnicity, education level, healthcare system of the populace, economic status, religious affiliations, and other aspects regarding the Japanese p ...
.
Some scholars have observed a dramatic increase in the proportion of young adult
In medicine and the social sciences, a young adult is generally a person in the years following adolescence, sometimes with some overlap. Definitions and opinions on what qualifies as a young adult vary, with works such as Erik Erikson's stages ...
s living with their parents in Mediterranean Europe
Southern Europe is also known as Mediterranean Europe, as its geography is marked by the Mediterranean Sea. Definitions of southern Europe include some or all of these countries and regions: Albania, Andorra, Bosnia and Herzegovina, Bulgaria, C ...
. This is a worrisome trend, since this shift in the timing of adult
An adult is an animal that has reached full growth. The biological definition of the word means an animal reaching sexual maturity and thus capable of reproduction. In the human context, the term ''adult'' has meanings associated with social an ...
hood could seriously affect the labor supply
In Mainstream economics, mainstream economic theories, the labour supply is the total hours (adjusted for intensity of effort) that workers wish to work at a given real wage rate. It is frequently represented graphically by a labour supply curve, ...
of young people, overall fertility rates
The total fertility rate (TFR) of a population is the average number of children that are born to a woman over her lifetime, if they were to experience the exact current age-specific fertility rates (ASFRs) through their lifetime, and they were t ...
, and European pay-as-you-go pension systems. This fact indicates that declining fertility rates in advanced economies may tend to be self-reinforcing and further exacerbate the situation.
A related concern is that high birth rates tend to place a greater burden of child rearing and education on populations already struggling with poverty. Consequently, inequality lowers average education and hampers economic growth. Also, in countries with a high burden of this kind, a reduction in fertility can hamper economic growth as well as the other way around. Richer countries have a lower fertility rate than poorer ones, and high income families have fewer kids than low-income ones.
Contrary findings
Every country could differ in their respective relationship between income and fertility. Some countries show that income and fertility are directly related but other countries show a directly inverse relationship.
A United Nations report in 2002 came to the conclusion that sharp declines in fertility rates in India, Nigeria
Nigeria, officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf of Guinea in the Atlantic Ocean to the south. It covers an area of . With Demographics of Nigeria, ...
, and Mexico occurred despite low levels of economic development
In economics, economic development (or economic and social development) is the process by which the economic well-being and quality of life of a nation, region, local community, or an individual are improved according to targeted goals and object ...
.
Vogl, T.S. provided the evidence that associations between income and fertility or between sibship size and education, that used to be positive in developing countries
A developing country is a sovereign state with a less-developed Secondary sector of the economy, industrial base and a lower Human Development Index (HDI) relative to developed countries. However, this definition is not universally agreed upon. ...
in the 20th century, recently became negative: first in Latin America, then in Asia, and finally in Africa. This is mainly explained by increased education levels.
Fertility declines have been seen during economic recession
In economics, a recession is a business cycle contraction that occurs when there is a period of broad decline in economic activity. Recessions generally occur when there is a widespread drop in spending (an adverse demand shock). This may be tr ...
s. This phenomenon is seen as a result of pregnancy postponement, especially of first births. But this effect can be short-term and largely compensated for during later times of economic prosperity.
Increased unemployment is generally associated with lower fertility. Nonetheless, in the years after the revolutions of 1989
The revolutions of 1989, also known as the Fall of Communism, were a revolutionary wave of liberal democracy movements that resulted in the collapse of most Communist state, Marxist–Leninist governments in the Eastern Bloc and other parts ...
in Russia, people who were more affected by labour market crises seemed to have a higher probability
Probability is a branch of mathematics and statistics concerning events and numerical descriptions of how likely they are to occur. The probability of an event is a number between 0 and 1; the larger the probability, the more likely an e ...
of having another child than those who were less affected. A study in France came to the result that employment instability has a strong and persistent negative effect on the final number of children for both men and women and contributes to fertility postponement for men. It also came to the result that employment instability has a negative influence on fertility among those with more egalitarian
Egalitarianism (; also equalitarianism) is a school of thought within political philosophy that builds on the concept of social equality, prioritizing it for all people. Egalitarian doctrines are generally characterized by the idea that all h ...
views about the division of labor but still a positive influence for women with more traditional views. This can be explained by the fact that countries with more traditional views of women's roles generally tend to have lower female labor force participation and higher fertility rates.
Another possible factor of lower fertility rates is culture. Numerous studies show that culture and ethnicity
An ethnicity or ethnic group is a group of people with shared attributes, which they Collective consciousness, collectively believe to have, and long-term endogamy. Ethnicities share attributes like language, culture, common sets of ancestry, ...
play a quantitatively
Quantitative research is a research strategy that focuses on quantifying the collection and analysis of data. It is formed from a deductive approach where emphasis is placed on the testing of theory, shaped by empiricist and positivist philos ...
significant role in explaining variation in women's work and fertility outcomes. Simultaneously, culture has a causal effect on economic development
In economics, economic development (or economic and social development) is the process by which the economic well-being and quality of life of a nation, region, local community, or an individual are improved according to targeted goals and object ...
. Such cultural traits as having trust in other people, appreciating the virtue of having tolerance and respect for others in children, feeling in control of one's life, and appreciating obedience in one's own children appear to be favorable to economic development
In economics, economic development (or economic and social development) is the process by which the economic well-being and quality of life of a nation, region, local community, or an individual are improved according to targeted goals and object ...
. Thus, the relationship between income and fertility may be not direct, but determined by a common root – cultural characteristics.
Mass culture
Popular culture (also called pop culture or mass culture) is generally recognized by members of a society as a set of practices, beliefs, artistic output (also known as popular art pop_art.html" ;"title="f. pop art">f. pop artor mass art, somet ...
can also influence people's attitudes toward having large families. For instance, in Brazil, where soap operas depict small families, women living in areas covered by the largest soap opera producer have significantly lower fertility rates. This effect is strongest among women of low socioeconomic status and in the central and late phases of fertility.
Two recent studies in the United States show, that in some circumstances, families whose income has increased will have more children. This may be explained by Fertility J-curve.
Fertility J-curve
Some scholars have recently questioned the assumption that economic development and fertility are correlated in a simple negative manner. A study published in ''Nature'' in 2009 found that when using the Human Development Index
The Human Development Index (HDI) is a statistical composite index of life expectancy, Education Index, education (mean years of schooling completed and expected years of schooling upon entering the education system), and per capita income i ...
instead of the GDP as measure for economic development, fertility follows a J-shaped curve: with rising economic development, fertility rates indeed do drop at first but then begin to rise again as the level of social and economic development increases while still remaining below the replacement rate
The total fertility rate (TFR) of a population is the average number of children that are born to a woman over her lifetime, if they were to experience the exact current age-specific fertility rates (ASFRs) through their lifetime, and they were t ...
.
In an article published in ''Nature
Nature is an inherent character or constitution, particularly of the Ecosphere (planetary), ecosphere or the universe as a whole. In this general sense nature refers to the Scientific law, laws, elements and phenomenon, phenomena of the physic ...
'', Myrskylä et al. pointed out that "unprecedented increases" in social and economic development in the 20th century had been accompanied by considerable declines in population growth rates and fertility. This negative association between human fertility and socio-economic development has been "one of the most solidly established and generally accepted empirical regularities in the social sciences". The researchers used cross-sectional and longitudinal analyses to examine the relationship between total fertility rate
The total fertility rate (TFR) of a population is the average number of children that are born to a woman over her lifetime, if they were to experience the exact current age-specific fertility rates (ASFRs) through their lifetime, and they were t ...
(TFR) and the human development index
The Human Development Index (HDI) is a statistical composite index of life expectancy, Education Index, education (mean years of schooling completed and expected years of schooling upon entering the education system), and per capita income i ...
(HDI).
The main finding of the study was that, in highly developed countries with an HDI above 0.9, further development halts the declining fertility rates. This means that the previously negative development-fertility association is reversed; the graph becomes J-shaped. Myrskylä et al. contend that there has occurred "a fundamental change in the well-established negative relationship between fertility and development as the global population entered the twenty-first century".
Some researchers doubt J-shaped relationship fertility and socio-economic development (Luci and Thevenon, 2010; Furuoka, 2009). For example, Fumitaka Furuoka (2009) employed a piecewise regression analysis to examine the relationship between total fertility rate and human development index. However, he found no empirical evidence to support the proposition that advances in development are able to reverse declining fertility rates. More precisely, he found that in countries with a low human development index, higher levels of HDI tend to be associated with lower fertility rates. Likewise, in countries with a high human development index, higher levels of HDI are associated with lower fertility rates, although the relationship is weaker. Furuoka's findings support the "conventional wisdom" that higher development is consistently correlated with lower overall fertility.
An update of Myrskylä et al.'s work has also found that declines in national fertility between 2010 and 2018 mean that there is now no long-term association between very high levels of development and sustained fertility rebounds.
The Easterlin hypothesis
The "Easterlin hypothesis" (Easterlin 1961, 1969, 1973) states that the positive relationship between income and fertility is dependent on relative income. It is considered the first viable and a still leading explanation for mid-twentieth century baby booms.
The hypothesis as formulated by Richard Easterlin
Richard Ainley Easterlin (January 12, 1926 – December 16, 2024) was an American economist. A professor of economics at the University of Southern California, he is best known for the economic theory named after him, the Easterlin paradox. Ano ...
presumes that material aspirations are determined by experiences rooted in family background: he assumes first that young couples try to achieve a standard of living
Standard of living is the level of income, comforts and services available to an individual, community or society. A contributing factor to an individual's quality of life, standard of living is generally concerned with objective metrics outsid ...
equal to or better than they had when they grew up. This is called "relative status". If income is high relative to aspirations and jobs are plentiful, it will be easier to marry young and have more children and still match that standard of living. But when jobs are scarce, couples who try to keep that standard of living will wait to get married and have fewer children. Children are normal goods
In economics, a normal good is a type of a Good (economics), good which experiences an increase in demand due to an increase in income, unlike inferior goods, for which the opposite is observed. When there is an increase in a person's income, for ...
once this influence of family background is controlled. For Easterlin, the size of the cohort is a critical determinant of how easy it is to get a good job. A small cohort means less competition, a large cohort means more competition to worry about. The assumptions blend economics
Economics () is a behavioral science that studies the Production (economics), production, distribution (economics), distribution, and Consumption (economics), consumption of goods and services.
Economics focuses on the behaviour and interac ...
and sociology
Sociology is the scientific study of human society that focuses on society, human social behavior, patterns of Interpersonal ties, social relationships, social interaction, and aspects of culture associated with everyday life. The term sociol ...
.
Easterlin's hypothesis can also be used for further predictions of the fertility rate. Easterlin expected a new fertility boom beginning in the 1980s.[Easterlin RA. 1979. What will 1984 be like? Socioeconomic implications of recent twists in age structure ''Demography'', 15: 397-432. DOI: 10.2307/2061197]
See also
* Advanced maternal age
Advanced maternal age, in a broad sense, is the instance of a woman being of an older age at a stage of reproduction, although there are various definitions of specific age and stage of reproduction.
The variability in definitions is in part e ...
* Fertility and intelligence
* Fertility factor (demography)
Fertility in colloquial terms refers the ability to have offspring. In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to reproduce, which is termed fecundity. The fertility rate ...
* Population growth
Population growth is the increase in the number of people in a population or dispersed group. The World population, global population has grown from 1 billion in 1800 to 8.2 billion in 2025. Actual global human population growth amounts to aroun ...
* Sub-replacement fertility
Sub-replacement fertility is a total fertility rate (TFR) that (if sustained) leads to each new generation being less populous than the older, previous one in a given area. The United Nations Population Division defines sub-replacement fertilit ...
* Total fertility rate
The total fertility rate (TFR) of a population is the average number of children that are born to a woman over her lifetime, if they were to experience the exact current age-specific fertility rates (ASFRs) through their lifetime, and they were t ...
References
Further reading
*
{{Economic paradoxes
Demographic economics
Demographics
Fertility