Fertility in

colloquial Colloquialism (also called ''colloquial language'', ''colloquial speech'', ''everyday language'', or ''general parlance'') is the linguistic style used for casual and informal communication. It is the most common form of speech in conversation amo ...

terms refers the ability to have

offspring In biology, offspring are the young creation of living organisms, produced either by sexual reproduction, sexual or asexual reproduction. Collective offspring may be known as a brood or progeny. This can refer to a set of simultaneous offspring ...

. In

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 ...

contexts, fertility refers to the actual production of offspring, rather than the physical capability to reproduce, which is termed

fecundity Fecundity is defined in two ways; in human demography, it is the potential for reproduction of a recorded population as opposed to a sole organism, while in population biology, it is considered similar to fertility, the capability to produc ...

. The

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 ...

is the average number of children born during an individual's lifetime. In medicine, fertility refers to the ability to have children, and

infertility In biology, infertility is the inability of a male and female organism to Sexual reproduction, reproduce. It is usually not the natural state of a healthy organism that has reached sexual maturity, so children who have not undergone puberty, whi ...

refers to difficulty in reproducing naturally. In general, infertility or subfertility in humans is defined as not being able to conceive a child after one year (or longer) of unprotected sex. The antithesis of ''fertility'' is

, while the antithesis of ''fecundity'' is sterility.

Demography

In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to produce which is termed

. While fertility can be measured, fecundity cannot be. Demographers measure the fertility rate in a variety of ways, which can be broadly broken into "period" measures and " cohort" measures. "Period" measures refer to a cross-section of the population in one year. "Cohort" data on the other hand, follows the same people over a period of decades. Both period and cohort measures are widely used.

Period measures

Crude birth rate Birth rate, also known as natality, is the total number of live human births per 1,000 population for a given period divided by the length of the period in years. The number of live births is normally taken from a universal registration syste ...

(CBR) - the number of live births in a given year per 1,000 people alive at the middle of that year. One disadvantage of this indicator is that it is influenced by the age structure of the population. * General fertility rate (GFR) - the number of births in a year divided by the number of women aged 15–44, times 1000. It focuses on the potential mothers only, and takes the age distribution into account. * Child-Woman Ratio (CWR) - the ratio of the number of children under 5 to the number of women 15–49, times 1000. It is especially useful in historical data as it does not require counting births. This measure is actually a hybrid, because it involves deaths as well as births. (That is, because of

infant mortality Infant mortality is the death of an infant before the infant's first birthday. The occurrence of infant mortality in a population can be described by the infant mortality rate (IMR), which is the number of deaths of infants under one year of age ...

some of the births are not included; and because of adult mortality, some of the women who gave birth are not counted either.) * Coale's Index of Fertility - a special device used in historical research

Cohort measures

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) - the total number of children a woman would bear during her lifetime if she were to experience the prevailing age-specific fertility rates of women. TFR equals the sum for all age groups of 5 times each ASFR rate. * Gross Reproduction Rate (GRR) - the number of girl babies a synthetic cohort will have. It assumes that all of the baby girls will grow up and live to at least age 50. * Net Reproduction Rate (NRR) - the NRR starts with the GRR and adds the realistic assumption that some of the women will die before age 49; therefore they will not be alive to bear some of the potential babies that were counted in the GRR. NRR is always lower than GRR, but in countries where mortality is very low, almost all the baby girls grow up to be potential mothers, and the NRR is practically the same as GRR. In countries with high mortality, NRR can be as low as 70% of GRR. When NRR = 1.0, each generation of 1000 baby girls grows up and gives birth to exactly 1000 girls. When NRR is less than one, each generation is smaller than the previous one. When NRR is greater than 1 each generation is larger than the one before. NRR is a measure of the long-term future potential for growth, but it usually is different from the current population growth rate.

Social and economic determinants of fertility

A parent's number of children strongly correlates with the number of children that each person in the next generation will eventually have. Factors generally associated with increased fertility include

religiosity The ''Oxford English Dictionary'' defines religiosity as: "Religiousness; religious feeling or belief. ..Affected or excessive religiousness". Different scholars have seen this concept as broadly about religious orientations and degrees of inv ...

, intention to have children, and maternal support. Factors generally associated with decreased fertility include

wealth Wealth is the abundance of valuable financial assets or physical possessions which can be converted into a form that can be used for transactions. This includes the core meaning as held in the originating Old English word , which is from an ...

, education,

female labor participation Since the Industrial Revolution, participation of women in the workforce outside the home has increased in industrialized nations, with particularly large growth seen in the 20th century. Largely seen as a boon for industrial society, women ...

, urban residence, cost of housing,

intelligence Intelligence has been defined in many ways: the capacity for abstraction, logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. It can be described as t ...

, increased female age and (to a lesser degree) increased male age. The "Three-step Analysis" of the fertility process was introduced by Kingsley Davis and Judith Blake in 1956 and makes use of three proximate determinants: The economic analysis of fertility is part of

household economics Household economics analyses all the decisions made by a household. These analyses are both at the microeconomic and macroeconomic level. This field analyses the structures of households, the behavior of family members, and their broader influence ...

, a field that has grown out of the

New Home Economics Gary Stanley Becker (; December 2, 1930 – May 3, 2014) was an American economist who received the 1992 Nobel Memorial Prize in Economic Sciences. He was a professor of economics and sociology at the University of Chicago, and was a leader of ...

. Influential economic analyses of fertility include Becker (1960), Mincer (1963), and Easterlin (1969). The latter developed 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 ba ...

to account for the Baby Boom.

Bongaarts' model of components of fertility

Bongaarts proposed a model where the total fertility rate of a population can be calculated from four proximate determinants and the total fecundity (TF). The index of marriage (Cm), the index of contraception (Cc), the index of induced abortion (Ca) and the index of postpartum infecundability (Ci). These indices range from 0 to 1. The higher the index, the higher it will make the TFR, for example a population where there are no induced abortions would have a Ca of 1, but a country where everybody used infallible contraception would have a Cc of 0. TFR = TF × Cm × Ci × Ca × Cc These four indices can also be used to calculate the total marital fertility (TMFR) and the total natural fertility (TN). TFR = TMFR × Cm TMFR = TN × Cc × Ca TN = TF × Ci ;Intercourse :The first step is

sexual intercourse Sexual intercourse (also coitus or copulation) is a sexual activity typically involving the insertion of the Erection, erect male Human penis, penis inside the female vagina and followed by Pelvic thrust, thrusting motions for sexual pleasure ...

, and an examination of the average age at first intercourse, the average frequency outside marriage, and the average frequency inside. ; Conception :Certain physical conditions may make it impossible for a woman to conceive. This is called "involuntary infecundity." If the woman has a condition making it possible, but unlikely to conceive, this is termed "subfecundity." Venereal diseases (especially

gonorrhea Gonorrhoea or gonorrhea, colloquially known as the clap, is a sexually transmitted infection (STI) caused by the bacterium ''Neisseria gonorrhoeae''. Infection may involve the genitals, mouth, or rectum. Gonorrhea is spread through sexual c ...

syphilis Syphilis () is a sexually transmitted infection caused by the bacterium ''Treponema pallidum'' subspecies ''pallidum''. The signs and symptoms depend on the stage it presents: primary, secondary, latent syphilis, latent or tertiary. The prim ...

, and

chlamydia Chlamydia, or more specifically a chlamydia infection, is a sexually transmitted infection caused by the bacterium ''Chlamydia trachomatis''. Most people who are infected have no symptoms. When symptoms do appear, they may occur only several w ...

) are common causes.

Nutrition Nutrition is the biochemistry, biochemical and physiology, physiological process by which an organism uses food and water to support its life. The intake of these substances provides organisms with nutrients (divided into Macronutrient, macro- ...

is a factor as well: women with less than 20% body fat may be subfecund, a factor of concern for

athletes An athlete is most commonly a person who competes in one or more sports involving physical strength, speed, power, or endurance. Sometimes, the word "athlete" is used to refer specifically to sport of athletics competitors, i.e. including trac ...

and people susceptible to

anorexia Anorexia nervosa (AN), often referred to simply as anorexia, is an eating disorder characterized by Calorie restriction, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin. Individuals wit ...

. Demographer Ruth Frisch has argued that "It takes 50,000 calories to make a baby". There is also subfecundity in the weeks following childbirth, and this can be prolonged for a year or more through

breastfeeding Breastfeeding, also known as nursing, is the process where breast milk is fed to a child. Infants may suck the milk directly from the breast, or milk may be extracted with a Breast pump, pump and then fed to the infant. The World Health Orga ...

. A furious political debate raged in the 1980s over the ethics of baby food companies marketing infant formula in developing countries. A large industry has developed to deal with subfecundity in women and men. An equally large industry has emerged to provide

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 ...

devices designed to prevent conception. Their effectiveness in use varies. On average, 85% of married couples using no contraception will have a

pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

in one year. The rate drops to the 20% range when using withdrawal, vaginal sponges, or spermicides. (This assumes the partners never forget to use the contraceptive.) The rate drops to only 2 or 3% when using the pill or an IUD, and drops to near 0% for implants and 0% for

tubal ligation Tubal ligation (commonly known as having one's "tubes tied") is a surgical procedure for female sterilization in which the fallopian tubes are permanently blocked, clipped or removed. This prevents the fertilization of eggs by sperm and thus the ...

( sterilization) of the woman, or a

vasectomy Vasectomy is an elective surgical procedure that results in male sterilization, often as a means of permanent contraception. During the procedure, the male vasa deferentia are cut and tied or sealed so as to prevent sperm from entering into ...

for the man. ;

Gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregn ...

:After a

fetus A fetus or foetus (; : fetuses, foetuses, rarely feti or foeti) is the unborn offspring of a viviparous animal that develops from an embryo. Following the embryonic development, embryonic stage, the fetal stage of development takes place. Pren ...

is conceived, it may or may not survive to birth. "Involuntary fetal mortality" involves natural abortion,

miscarriage Miscarriage, also known in medical terms as a spontaneous abortion, is an end to pregnancy resulting in the loss and expulsion of an embryo or fetus from the womb before it can fetal viability, survive independently. Miscarriage before 6 weeks ...

s and

stillbirth Stillbirth is typically defined as fetus, fetal death at or after 20 or 28 weeks of pregnancy, depending on the source. It results in a baby born without vital signs, signs of life. A stillbirth can often result in the feeling of guilt (emotio ...

(a fetus born dead). Human intervention intentionally causing abortion of the fetus is called "

therapeutic 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 pregnanc ...

In medicine

In medicine, the definition of fertility is "the capacity to establish a clinical pregnancy." Women have

hormonal A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physiology and behavior. Hormones a ...

cycles which determine when they can achieve

. The cycle is approximately twenty-eight days long, with a fertile period of five days per cycle, but can deviate greatly from this norm. Men are fertile continuously, but their

sperm quality Semen quality is a measure of male 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, ...

is affected by their health, frequency of ejaculation, and environmental factors. Fertility declines with age in both sexes. For women, the decline begins around the age of 32, and becomes precipitous at age 37. For men, potency and sperm quality begins to decline around the age of 40. Even if an older couple does manage to conceive a child, the pregnancy will be increasingly difficult for the mother, and carries a higher risk of

birth defect A birth defect is an abnormal condition that is present at birth, regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can range from mild to severe. Birth de ...

s and

genetic disorder A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosome abnormality. Although polygenic disorders ...

s for the child. Pregnancy rates for sexual intercourse are highest when it occurs every 1 or 2 days, or every 2 or 3 days. Studies have found no significant difference between different sex positions and pregnancy rate, as long as it results in

ejaculation Ejaculation is the discharge of semen (the ''ejaculate''; normally containing sperm) from the penis through the urethra. It is the final stage and natural objective of male sexual stimulation, and an essential component of natural conception. ...

into the

vagina In mammals and other animals, the vagina (: vaginas or vaginae) is the elastic, muscular sex organ, reproductive organ of the female genital tract. In humans, it extends from the vulval vestibule to the cervix (neck of the uterus). The #Vag ...

Menstrual cycle

A woman's menstrual cycle begins, as arbitrarily assigned, with menses. Next is the follicular phase where estrogen levels build as an ovum matures (due to the follicular stimulating hormone, or FSH) within the ovary. When estrogen levels peak, it spurs a surge of luteinizing hormone (LH) which completes maturation and enables the ovum to break through the ovary wall. This is ovulation. During the luteal phase following ovulation LH and FSH cause the post-ovulation ovary to develop into the corpus luteum which produces progesterone. The production of progesterone inhibits the LH and FSH hormones which (in a cycle without pregnancy) causes the corpus luteum to atrophy, and menses to begin the cycle again. Peak fertility occurs during just a few days of the cycle: usually two days before and two days after the ovulation date. This fertile window varies from woman to woman, just as the ovulation date often varies from cycle to cycle for the same woman. The

ovule In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the ''nucellus'' (or remnant of the sporangium, megasporangium), ...

is usually capable of being fertilized for up to 48 hours after it is released from the

ovary The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/ oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are end ...

Sperm Sperm (: sperm or sperms) is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm ...

survive inside the

uterus The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the hollow organ, organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic development, embryonic and prenatal development, f ...

between 48 and 72 hours on average, with the maximum being 120 hours (5 days). These periods and intervals are important factors for couples using the rhythm method of contraception.

Female fertility

The average age of

menarche Menarche ( ; ) is the first menstrual cycle, or first menstruation, menstrual bleeding, in female humans. From both social and medical perspectives, it is often considered the central event of female puberty, as it signals the possibility of fe ...

in the United States is about 12.5 years. In postmenarchal girls, about 80% of the cycles are

anovulatory Anovulation is when the ovaries do not release an oocyte during a menstrual cycle. Therefore, ovulation does not take place. However, a woman who does not ovulate at each menstrual cycle is not necessarily going through menopause. Chronic anovul ...

(ovulation does not actually take place) in the first year after menarche, 50% in the third and 10% in the sixth year.

Menopause Menopause, also known as the climacteric, is the time when Menstruation, menstrual periods permanently stop, marking the end of the Human reproduction, reproductive stage for the female human. It typically occurs between the ages of 45 and 5 ...

occurs during a woman's midlife between ages 48 and 55. During menopause, hormonal production by the ovaries is reduced, eventually causing a permanent cessation of the creation of the uterine lining (period). This is considered the end of the fertile phase of a woman's life. The predicted effect of age on female fertility in women trying to get pregnant, without using fertility drugs or in vitro fertilization:A computer simulation run by Henri Leridon, PhD, an epidemiologist with the French Institute of Health and Medical Research: * * At age 30 ** 75% will conceive ending in a live birth within one year ** 91% will conceive ending in a live birth within four years. * At age 35 ** 66% will conceive ending in a live birth within one year ** 84% will conceive ending in a live birth within four years. * At age 40 ** 44% will conceive ending in a live birth within one year ** 64% will conceive ending in a live birth within four years. Studies of couples trying to conceive have yielded better results: one 2004 study of 770 European women found that 82% of 35- to 39-year-old women conceived within a year, while a study in 2013 of 2,820 Danish women saw 78% of 35- to 40-year-olds conceive within a year. According to an opinion by the Practice Committee of the American Society for Reproductive Medicine, specific coital timing or position, and resting supine after intercourse have no significant impact on fertility. Sperm can be found in the cervical canal seconds after ejaculation, regardless of coital position. Successful pregnancies facilitated by fertility treatment have been documented in women as old as 67.

Male fertility

Some research suggests that older males have decreased semen volume,

sperm motility Sperm motility describes the ability of sperm to move properly through the female reproductive tract (internal fertilization) or through water ( external fertilization) to reach the egg. Sperm motility can also be thought of as the ''quality'', wh ...

, and impaired sperm morphology. In studies that controlled for female partner's age, comparisons between men under 30 and men over 50 found relative decreases in

pregnancy rate Pregnancy rate is the success rate for getting pregnant. It is the percentage of all attempts that leads to pregnancy, with attempts generally referring to menstrual cycles where insemination or any artificial equivalent is used, which may be simpl ...

s between 23% and 38%. Sperm count declines with age, with men aged 50–80 years producing sperm at an average rate of 75% compared with men aged 20–50 years and larger differences exist in the number of

seminiferous tubules Seminiferous tubules are located within the testicles, and are the specific location of meiosis, and the subsequent creation of male gametes, namely spermatozoa. Structure The epithelium of the tubule consists of a type of sustentacular cells ...

in the

testes A testicle or testis ( testes) is the gonad in all male bilaterians, including humans, and is homologous to the ovary in females. Its primary functions are the production of sperm and the secretion of androgens, primarily testosterone. The ...

containing mature sperm: * In males 20–39 years old, 90% of the seminiferous tubules contain mature sperm. * In males 40–69 years old, 50% of the seminiferous tubules contain mature sperm. * In males 80 years old and older, 10% of the seminiferous tubules contain mature sperm. Decline in male fertility is influenced by many factors, including lifestyle, environment and psychological factors. Some research suggests increased risks for health problems for children of older fathers, but no clear association has been proven. A large scale study in

Israel Israel, officially the State of Israel, is a country in West Asia. It Borders of Israel, shares borders with Lebanon to the north, Syria to the north-east, Jordan to the east, Egypt to the south-west, and the Mediterranean Sea to the west. Isr ...

suggested that the children of men 40 or older were 5.75 times more likely than children of men under 30 to have an

autism spectrum disorder Autism, also known as autism spectrum disorder (ASD), is a neurodevelopmental disorder characterized by differences or difficulties in social communication and interaction, a preference for predictability and routine, sensory processing di ...

, controlling for year of birth, socioeconomic status, and maternal age. Increased paternal age has been suggested to correlate with

schizophrenia Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...

but it is unproven. Australian researchers have found evidence to suggest

obesity Obesity is a medical condition, considered by multiple organizations to be a disease, in which excess Adipose tissue, body fat has accumulated to such an extent that it can potentially have negative effects on health. People are classifi ...

may cause subtle damage to sperm and prevent a healthy pregnancy. They reported fertilization was 40% less successful when the father was overweight. The American Fertility Society recommends an age limit for sperm donors of 50 years or less, and many

fertility clinic Fertility clinics are medical clinics that assist couples, and sometimes individuals, who want to become parents but for medical reasons have been unable to achieve this goal via the natural course. Clinics apply a number of diagnosis tests and ...

s in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

will not accept donations from men over 40 or 45 years of age.Age Limit of Sperm Donors in the United Kingdom
Pdf file

Historical trends by country

France

The French pronatalist movement from 1919 to 1945 failed to convince French couples they had a

patriotic Patriotism is the feeling of love, devotion, and a sense of attachment to one's country or state. This attachment can be a combination of different feelings for things such as the language of one's homeland, and its ethnic, cultural, politic ...

duty to help increase their country's birthrate. Even the government was reluctant to support the movement. Only between 1938 and 1939 did the French government become directly and permanently involved in the pronatalist effort. Although the birthrate started to surge in late 1941, the trend was not sustained. Falling birthrate again became a major concern among demographers and government officials in the 1970s. In mid-2018, there was a bill introduced to legalize single women and lesbian couples to get fertility treatment. At the beginning of 2020, the Senate approved the bill 160 votes to 116. They are a step closer to legalizing fertility treatments for all women regardless of sexual orientation or marital status. Soon there will be no reason for lesbian couples or single women to travel to be able to start their own family.

Korea

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia. It constitutes the southern half of the Korea, Korean Peninsula and borders North Korea along the Korean Demilitarized Zone, with the Yellow Sea to the west and t ...

has the lowest fertility rate in the world at 0.78. A variety of explanations have been proposed, ranging from investment in education to

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 ...

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 ...

, a decline in the marriage rate,

divorce Divorce (also known as dissolution of marriage) is the process of terminating a marriage or marital union. Divorce usually entails the canceling or reorganising of the legal duties and responsibilities of marriage, thus dissolving the M ...

, female participation in the labor force, and the

1997 Asian financial crisis The 1997 Asian financial crisis gripped much of East Asia, East and Southeast Asia during the late 1990s. The crisis began in Thailand in July 1997 before spreading to several other countries with a ripple effect, raising fears of a worldwide eco ...

. After being legal from the 1960s to the 1980s, abortion was again made illegal in South Korea in the early 2000s in an attempt to reverse the declining fertility rate.

United States

From 1800 to 1940, fertility fell in the US. There was a marked decline in fertility in the early 1900s, associated with improved contraceptives, greater access to contraceptives and sexuality information and the "first"

sexual revolution The sexual revolution, also known as the sexual liberation, was a social movement that challenged traditional codes of behavior related to sexuality and interpersonal relationships throughout the Western world from the late 1950s to the early 1 ...

in the 1920s.

Post-WWII

After 1940 fertility suddenly started going up again, reaching a new peak in 1957. After 1960, fertility started declining rapidly. In the Baby Boom years (1946–1964), women married earlier and had their babies sooner; the number of children born to mothers after age 35 did not increase.

Sexual revolution

After 1960, new methods of contraception became available, the ideal family size fell, from 3 to 2 children. Couples postponed marriage and first births, and they sharply reduced the number of third and fourth births.

References

External links

* * * * Calder, Vanessa Brown, and Chelsea Follett (August 10, 2023)
Freeing American Families: Reforms to Make Family Life Easier and More Affordable
''Policy Analysis'' no. 955, Cato Institute, Washington, DC. {{Authority control Demographics Sexual health