Income Income is the consumption and saving opportunity gained by an entity within a specified timeframe, which is generally expressed in monetary terms. Income is difficult to define conceptually and the definition may be different across fields. Fo ...

and

fertility Fertility is the capability to produce offspring through reproduction following the onset of sexual maturity. The fertility rate is the average number of children born by a female during her lifetime and is quantified demographically. Fertili ...

is the

association Association may refer to: *Club (organization), an association of two or more people united by a common interest or goal *Trade association, an organization founded and funded by businesses that operate in a specific industry *Voluntary associatio ...

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 would be born to a woman over her lifetime if: # she were to experience the exact current age-specific fertility rates (ASFRs) through her lifetime # she were t ...

within and between nations. The higher the degree of

education Education is a purposeful activity directed at achieving certain aims, such as transmitting knowledge or fostering skills and character traits. These aims may include the development of understanding, rationality, kindness, and honesty ...

and

GDP Gross domestic product (GDP) is a monetary measure of the market value of all the final goods and services produced and sold (not resold) in a specific time period by countries. Due to its complex and subjective nature this measure is ofte ...

per capita of a human

population Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using a ...

, 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). As ...

, the fewer children are born in any developed country. In a 1974 United Nations population conference in Bucharest,

Karan Singh Karan Singh (born 9 March 1931) is an Indian politician and philosopher. He is the son of the last ruling Maharaja of the princely state of Jammu and Kashmir, Sir Hari Singh. He was the prince regent of Jammu and Kashmir until 1952. From 1 ...

, a former minister of population in India, illustrated this trend by stating "Development is the best contraceptive."

Demographic-economic paradox

Herwig Birg has called the inverse relationship between income and fertility a “demo-economic

paradox A paradox is a logically self-contradictory statement or a statement that runs contrary to one's expectation. It is a statement that, despite apparently valid reasoning from true premises, leads to a seemingly self-contradictory or a logically u ...

”''.''

Evolutionary biology Evolutionary biology is the subfield of biology that studies the evolutionary processes ( natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life ...

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 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.

Individual level observations

In the years after the

revolutions of 1989 The Revolutions of 1989, also known as the Fall of Communism, was a revolutionary wave that resulted in the end of most communist states in the world. Sometimes this revolutionary wave is also called the Fall of Nations or the Autumn of Nat ...

in Russia, people who were more affected by labour market crises seemed to have a higher probability of having another child than those who were less affected.

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 Life expectancy is a statistical measure of the average time an organism is expected to live, based on the year of its birth, current age, and other demographic factors like sex. The most commonly used measure is life expectancy at birth ...

, reduced child mortality, improved female literacy and independence, and

urbanization Urbanization (or urbanisation) refers to the population shift from rural to urban areas, the corresponding decrease in the proportion of people living in rural areas, and the ways in which societies adapt to this change. It is predominantly t ...

that all result from increased GDP per capita, consistent with the

demographic transition model In demography, demographic transition is a phenomenon and theory which refers to the historical shift from high birth rates and high death rates in societies with minimal technology, education (especially of women) and economic development, to lo ...

. 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 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. 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 largest Christian church, with 1.3 billion baptized Catholics worldwide . It is among the world's oldest and largest international institutions, and has played a ...

couples but is associated with slightly decreased fertility among

Protestant Protestantism is a branch of Christianity that follows the theological tenets of the Protestant Reformation, a movement that began seeking to reform the Catholic Church from within in the 16th century against what its followers perceived to b ...

couples.Page 238
/ref> 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 more 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.

Ansley Coale Ansley Johnson Coale (November 14, 1917 – November 5, 2002), was one of America's foremost demographers. A native to Baltimore, Maryland, he earned his Bachelor of Arts in 1939, his Master of Arts in 1941, and (after a period of service i ...

'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 or abortions.

Consequences

Across countries, there is a strong negative correlation between

gross domestic product Gross domestic product (GDP) is a monetary measure of the market value of all the final goods and services produced and sold (not resold) in a specific time period by countries. Due to its complex and subjective nature this measure is oft ...

and

, 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. 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 Inequality may refer to: Economics * Attention inequality, unequal distribution of attention across users, groups of people, issues in etc. in attention economy * Economic inequality, difference in economic well-being between population groups * ...

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. Demographic-TransitionOWID

Contrary findings

United Nations The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and security, develop friendly relations among nations, achieve international cooperation, and be a centre for harmoniz ...

report in 2002 came to the conclusion that sharp declines in fertility rates in India, Nigeria, and Mexico occurred despite low levels of economic development. 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. Increased unemployment is generally associated with lower fertility. 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 (), or equalitarianism, is a school of thought within political philosophy that builds from the concept of social equality, prioritizing it for all people. Egalitarian doctrines are generally characterized by the idea that all hu ...

views about the division of labor but still a positive influence for women with more traditional views. Fertility declines have been seen during economic

recession In economics, a recession is a business cycle contraction when there is a general decline in economic activity. Recessions generally occur when there is a widespread drop in spending (an adverse demand shock). This may be triggered by various ...

s. This phenomenon is seen as a result of pregnancy postponement, especially of first births. However, this effect can be short-term and largely compensated for during later times of economic prosperity. Two recent studies in the United States show, that in some circumstances, families whose income has increased will have more children.

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 statistic composite index of life expectancy, education (mean years of schooling completed and expected years of schooling upon entering the education system), and per capita income indicators, wh ...

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 would be born to a woman over her lifetime if: # she were to experience the exact current age-specific fertility rates (ASFRs) through her lifetime # she were t ...

In an article published in ''

Nature Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are ...

'', 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

(TFR) and the

human development index The Human Development Index (HDI) is a statistic composite index of life expectancy, education (mean years of schooling completed and expected years of schooling upon entering the education system), and per capita income indicators, wh ...

(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 In statistical modeling, regression analysis is a set of statistical processes for estimating the relationships between a dependent variable (often called the 'outcome' or 'response' variable, or a 'label' in machine learning parlance) and one ...

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.

References

External links

* {{Economic paradoxes Demographic economics Demographics Fertility