Glossary

Abortion causes a fertilized egg to fail to implant in the uterus, or it causes an embryo or fetus to die.

Abstinence means not having sexual relations with another person.

Age-specific fertility rates (ASFR) pertain to specific age groups. For example, the ASFR for 15-19 year-olds is the number of live births experienced by women ages 15-19 during the year, divided by the midyear population of women ages 15-19, all multiplied by 1000.

Age-specific mortality rates (ASMR) pertain to different age groups. For example, the mortality rate for 95-99 year-old women is the number of 95-99 year-olds who die during the year, divided by the midyear population of women ages 95-99, all multiplied by 1000.

The Aged Dependency Ratio is the number of people of retirement age divided by the number of people of working-age. The number of people of retirement age is typically taken to be people sixty-five years of age and older.

Birth control comprises many different ways to avoid having children, including abstinence,
contraception, abortion, and sterilization.

The birth rate is the number of live births during the year, divided by the midyear population, all multiplied by 1000.

The Black-White Crossover Effect is the phenomenon of Black people age x having more expected life years remaining than White people age x, for x>75 years of age

Brain-drain occurs when talented, wealthy, or otherwise useful citizens emigrate to another
community or another country

Bride price is a payment from the man's family to the woman's family upon the occasion of their marriage

In this text, capital shallowing refers to any decrease in the capital-to-labour ratio that is due to increases in the size of the labour force.

Ceteris paribus is a Latin phrase meaning "all other things being equal" or "holding everything else constant".

See "Young Dependency Ratio".

Chronic deaths are the result of usual conditions and include the usual incidence of endemic diseases like chicken pox, pneumonia, and stroke.

Chronic living conditions are everyday living conditions, with the usual risks of dying.

Cohabitation refers to adults living together in a sexual relationship without being legally married.

A cohort is a group of people born during the same time period, typically one year.

The completed fertility rate is the average number of children per woman, for women belonging to a particular cohort. It cannot be computed until the women have completed their childbearing years, typically assumed to be age 50. Thus, after 2025 we can compute the completed fertility rate for women born in 1975.

Consumer surplus is the amount by which the amount paid by buyers falls short of what they would have been willing to pay. It is measured as the area between the Demand curve and the price or wage.

Contraception prevents sperm from fertilizing an ovum.

Crisis deaths are deaths caused by unusual situations such as natural disasters and wars.

The crude birth rate is the birth rate as defined above under "birth rate", without any adjustments having been made.

The crude death rate is the death rate as defined below under "death rate", without any adjustments having been made.

The death rate is the number of deaths in the population during the year, divided by the midyear population, all multiplied by 1000.

The Demographic Dividend is the material benefits a society may reap when it has a low Total Dependency Ratio. See Chapters 16 and 17 for details.

The Demographic Transition is a process of change in birth and death rates. It is associated with industrialization and secularization. By the end of the Demographic Transition, birth and death rates are much lower than they were before the Demographic Transition

The Demographic Trap, illustrated in Figure 15-3, is a situation in which low educational achievement for women is correlated with high fertility. For details, see Chapter 15.

See Chapter 22 for a traditional and a modern statement of Domar's Hypothesis.

Doubling time is the length of time it takes for a population (or anything else) to double. It can be approximated by the formula 70/r, where r is the growth rate expressed as a percentage.

See groom price.

Emigration refers to people leaving a country.  In a national context, the word  "emigrant" is usually reserved for people leaving the country permanently.

Eugenics is a program of altering the human gene pool by encouraging some kinds of people to have children and some kinds of children to be born, predicated on the belief that genes are the most important thing about a person and that we can understand what the human gene pool needs to become

Deaths over and above the usual number of deaths are called "excess deaths". To find the number of excess deaths, we have to estimate the number of chronic deaths, i.e. how many deaths we would normally expect.

Expected life years remaining depends on a person's age. For a person age x, expected life years remaining is the number of additional years of life the average person age x can expect to experience, assuming that mortality rates do not change from today's levels

The expected real wage is the probability-weighted sum of the different possible after-tax real wages or incomes you might receive in a particular location.

External economies of scale refers to the profits a firm can realize by being part of a group of similar firms located near one another.

Fecundity is the physiological ability to conceive, have a successful pregnancy, and give birth.

Fertility refers to how many biological children people have. See Age-specific fertility rate, Completed fertility rate, General fertility rate, and Total fertility rate for some precise definitions.

The fertility gap is the difference in a cohort's self-professed intended fertility rate and their completed fertility rate.

The Fertility Trap is a situation where postponing or discouraging childbearing at one time makes having children more difficult later on, to a degree that was not anticipated.

The word "fiscal" refers to government budgets. The net fiscal cost of an immigrant is the money the government spends on them and how much of the nation's shared infrastructure they use, minus the taxes the immigrant pays to the government.

fundamental equation of population growth:
population growth during the year = number of people who were born - number of people who died + number of people who immigrated - number of people who emigrated

The general fertility rate is the number of live births during the year, divided by the midyear population of women of child-bearing age, all multiplied by 1000.

A generational account for a person age x, evaluated in year y, is the present value (at year y) of all the taxes and all the transfers the average person age x will have to pay as time t progresses from date y to the end of the person's life. It is the net tax that a person age x owes from now on, measured in today's dollars.

Genuine Savings, also known as Adjusted Net Saving, is an estimate of changes to a nation's income-generating capacity. If Genuine Savings is positive, then the nation is building up its various forms of capital and its ability to earn income/produce output. If Genuine Savings is negative, then the nation is dissipating its capital and its ability to earn income. See Chapter 18 for the calculation.

Groom price is a payment from a woman's family to a man's family on the occasion of their marriage.

The Gross Reproduction Rate is the number of female babies the average woman can be expected to have, based on today's age-specific fertility rates and sex ratio at birth.

Health-Adjusted Life Expectancy at age x is expected life years remaining for the average person age x, adjusted for how healthy those life years will be.

This Hispanic Paradox refers to the fact that, in the United States, people of Hispanic origin live longer than "non-Hispanic Whites", even though they are, on average, lower-income than non-Hispanic Whites.

Immigration refers to people entering a country.  In a national context, the word  "immigrant" is usually reserved for people coming through legal channels, and coming to stay permanently.

The income effect of a wage change is the degree to which it causes people to feel wealthier and spend more on something.

Indenture is the state of being contracted to another person or a firm to work without pay for a specified period of time.

Infant mortality describes the age-specific mortality rate for babies during their first twelve months of life.

Intergenerational fairness means treating different cohorts of people equitably. One definition of intergenerational fairness is that each cohort or each generation of people can expect the same net tax burden over their lifetime, i.e. the same generational account at birth.

Internal economies of scale refers to the profit a firm can earn by expanding its operations to the point where its average cost per unit produced is lowest.

The intrinsic rate of natural increase is the population growth rate that will eventually emerge when fertility rates and mortality rates are unchanged for a sufficiently long time and there is no migration.

Labour productivity is a measure of how much output is produced per unit of labour.  Labour units are usually hours worked.

A Leslie matrix contains fertility and survival information about a population. It is used mathematically to transform today's population count by age to next year's population count by age, assuming no migration.

Life expectancy refers to expected life years remaining for the average person age x.  If age is not specified, life expectancy refers to expected life years remaining for the average newborn.

The Life Table computes expected life years remaining for each age group using age-specific mortality rates. It assumes that age-specific mortality rates will not change.

Migration refers to the movement of people from one place to another.  See Emigration, Immigration, and Net Migration for more specific definitions.

The minimum efficient scale for a firm is reached when the amount of output it produces coincides with its lowest average cost per unit.

Model Life Tables are generalized Life Tables for a particular group of countries, based on their typical age-specific mortality rates.

Mortality refers to death. See Age-specific mortality, Crude death rate, Expected life years remaining, and Standardized death rate for more specific definitions.

Natural increase is the number of births during a period of time, typically a year, minus the number of deaths during that same period of time.

Net migration is the number of immigrants during a period of time minus the number of emigrants during that same period of time.

The net migration rate is the number of immigrants (net of emigrants) during the year, divided by the midyear population, all multiplied by 1000. This number will be negative if there were more emigrants than immigrants.

The Net Reproduction Rate is the the number of female children - who survive to their mother's age - that the average woman can be expected to have, given today's age-specific fertility rates, today's sex ratio, and today's age-specific mortality rates.

The Paradox of the Life Table occurs whenever an older age group has a greater number of expected life years remaining than does a younger age group.

The Pareto criterion is one of the norms of Economics, though it is often ignored.  It says that one situation cannot be preferred to another if someone will be made worse off.  For a situation to be preferable, someone must be made better off and no one can be made worse off.  Thus, for a new situation to be preferred to an existing situation, there must be enough gain available to compensate those who are hurt by the change, and the compensation must take place.

A peasant is a farmer without much social status who owns or rents a small area of land.

Polygyny occurs when it is normal for men to be married to multiple women at the same time.

Population momentum is the population growth or shrinkage due to existing cohorts of people surviving to childbearing age, with the number of people of childbearing age consequently growing or shrinking.

A population pyramid is a two-dimension object showing a population's age structure and its biological sex ratio at each age. For examples, see Chapter 15.

The amount you would be willing to pay today for the privilege of receiving $x tomorrow will be some $y<$x. We say that this $y is the present value of $x. Generally, we calculate the present value of $x received t years from now to
be equal to $x divided by j, where j =(1+r) raised to the exponent t. "r" is the relevant interest rate. An additional adjustment can be made for inflation.

Producer surplus is the benefit received by workers or sellers over,-and-above the minimum they require to provide the service or good. It is calculated as the difference between the wage received and the lowest acceptable wage, for the entire quantity supplied at that wage.

Real income is income divided by a price index.  The price index measures the cost of living.  Thus, your real income measures how much stuff you can buy with your income.

The real wage is the wage divided by a price index.  The price index measures the cost of living.  Thus your real wage measures the stuff you can buy for each hour worked.

Remittances are monies earned by citizens of country x who work abroad temporarily, or gifts of cash to citizens of country x by those who no longer live in country x.

Replacement exists when the average woman is expected to generate one or more female children by age x who will also survive to age x.  A Total Fertility Rate of 2.1 children per woman is usually enough to guarantee replacement.

Serfs are legally bound to a piece of land and have obligations to work that land for the landlord.

The sex ratio has been defined only in binary terms and relies on official documents recording each person's sex. It is the number of males divided by the number of females. It is often expressed as the number of males for every 100 females.

see "stable population"

A stable population is one where there is no migration, and fertility rates and mortality rates have been constant for enough time to make the birth and death rates constant also.  With constant birth and death rates, the population growth rate is constant.  The age structure is constant as well, with each age group growing at the same constant rate of population growth, known as the intrinsic rate of natural increase.
In the special case of a stationary population, the population growth rate is zero.

The standard of living measures how well off people are, materially speaking. It refers generally to the quantity and quality of food, housing, medical care, education, and recreation that they can afford.

Death rates can be adjusted to account for differences in countries that might bias the crude death rate. A death rate is that is adjusted in this way is called a standardized death rate. Death rates can be standardized for age, sex, or other factors.

A stationary population is a stable population that has its birth rate equal to its death rate. See "stable population".

Sterilization renders someone incapable of having children. Two medical procedures that accomplish sterilization are tubal ligation (for biological women) and vasectomy (for biological men).

The substitution effect of a wage change is the degree to which it causes people to feel their time is more valuable. Due to the substitution effect, they will work more and cut back on leisure, child care, or other time-intensive activities.

Tempo-adjusted TFR is the Total Fertility Rate (TFR) adjusted for the fact that the average age of mothers is changing. The definition and a calculation can be found in Chapter 11.

The Total Dependency Ratio is the number of people not of working age divided by the number of people of working age. It is typically calculated as the number of people under fifteen years of age or over sixty-five years of age, divided by the number of people ages 15-64.

The Total Fertility Rate is the number of biological children the average woman is expected to have during her lifetime.  It is an estimate based on today's age-specific fertility rates.

Total Hotelling Rent is equal to rent multiplied by quantity, where rent = price minus marginal cost on the last unit sold, and quantity is the total amount of resource extracted during the period.

The Value of a Statistical Life (VSL) is a dollar value assigned to a statistical life saved or lost. A statistical life is the life of an unknown person who is a member of a large group of people who experience similar risks of dying. The VSL is calculated using people's willingness to pay for a reduced chance of dying.

The Young Dependency Ratio is the number of people too young to work divided by the number of people of working-age. Typically, people too young to work are defined as being less than fifteen years old.