New Society Chapter 17: Population,Aging and Health
One of the most important features of any society is the number of people and the
relative size of the various subgroups.
When populations grow or shrink, and when subgroups change in relative size,
serious repercussions follow.
Aging is another key feature of the changing relative size of various subgroups of
While aging is a long-term phenomenon that has been taking place for more than a
century, there are different stages which have different consequences.
First aging largely involved fewer numbers of children. Changing sizes of age
groups implied difficult accommodations in the school system, in a broad sense
adults were freer, given that they had fewer children to care for. These changes
both maximized the proportion of the population that was at an employable age
and freed women from family preoccupations, encouraging them to participate in
the labor force. These trends permitted an expansion of the social programs that
depend on revenues from the taxation of employed persons.
At later stages of aging it is no longer the relative size of the population of labor-
force age that is growing, but rather the number of seniors. When the population at
labor-force ages is growing, and real incomes are increasing, it is not hard to
enrich social programs, such as health and pensions that benefit the elderly.
Health status is another phenomenon that can be studied from the point of view of
population change. Well-being in society is often analyzed through income and its
distribution or through conflict, crime and victimization through population
The comparison of the relative health status of various sectors of the population
permits an analysis of the differences across groups, and this point to the
dynamics of well-being. (E.g. The higher life expectancy of married persons can
be analyzed in terms of the protective role of marriage. Married persons benefit
from having someone who can help in times of illness, and married men, in
particular, benefit from having better diets and lower levels of risk behavior than
We can also look at the consequences of population change at the level of the total
human population. Biologists measure change over millions of years and the
human presence which was once insignificant, can be seen as changing the
environment of the planet.
Acohort is a group of people, observed through time, who share a common temporal demographic experience.
The Study of Population
Fertility: Being born
Migration: Moving around
Mortality: To die
These events mark a persons life-course.
Although these events are clearly experienced by individuals, added together
they also show the development of societies over time.
At the group level, fertility and immigration are the basic mechanisms through
which populations, countries, societies and communities are regenerated.
These regenerative processes add numbers to the population, ensuring
demographic continuity in the face of departures through death and
They also change the character of the population and consequently of the
Character of the population: Can be changed in terms of age and sex
structure, socioeconomic composition, cultural make-up and regional
Population and Policy
Society has interest in ensuring that population dynamics operate to produce
an overall net benefit.All societies attempt to shape the decision making
framework of individuals to promote this common benefit.
With respect to fertility, behavior that promotes reproduction will sometimes
be encouraged and sometimes constrained.
With respect to mortality, behavior that will prolong a persons life in the
society will be encouraged and the society will often take some responsibility
for the health and safety of its citizens.
With respect to immigration, the society as a whole will typically establish
structures, policies, and rules through which entry are controlled in order to
produce a social benefit.
Population States and Processes
Demography: The study of populations- their size, distribution and
composition- and the immediate factors causing population change (births,
deaths, and migration).
Population stock or the state of population: refers to the size distribution, and composition of the population at a given point in time.
Flow or the population processes: The three ways in which populations
change from one time to another, through births, deaths and migration.
Links between Population States ad Processes
Population states and processes are dynamically interrelated. (E.g. Lower birth
rates (a process) produce an older population (a state).
Achange in population size- a change from one state to a second state- is
clearly a function of intervening births, deaths, immigration and emigration.
Natural increase or decrease: Births minus deaths.
Net migration: Immigration minus emigration
The basic equation for population at a given time is as follows:
P2 represents the population at a given time; P1, the population at an earlier
time; B, the number of births in the interval; D, the number of deaths in the
interval; I, the number of immigrants who arrived in the interval; and E, the
number of emigrants who departed in the interval.
We could analyze the change in composition by marital status, educational
attainment, or labor-force status.
Health status may be studied in terms of the transitions from states of good to
Population Growth at the World Level
Human history can usefully be divided into segments characterized by
different population growth dynamics.
Ten thousand years ago, people lived in hunting-and-gathering societies. It
appears that the long-term growth dynamics in those societies were minimal.
There were probably periods of growth, but there were other times of high
mortality due to conquest, famine, or disease.
Fertility was also considerably less than the biological maximum because
births needed to be spaced to ensure the survival of infants.
The difficulty of finding soft food for children and the consequent need for
long periods of lactation kept average births per woman in the range of five or
TheAgricultural Revolution which began 10000 to 12000 years ago
involved the emergence of agriculture and the domestication of animals,
allowing more people to be supported by the environment.
The more secure food supply would have reduced deaths, but famines associated with climatic conditions were still common.
Increased population density furthered the spread of infectious diseases.
It would appear that the agricultural revolution brought more deaths from all
causes except inadequate nutrition.
The number of births probably increased as the availability of softer foods
made shorter lactation periods possible.
The European population expansion was the next period which went on for
2 centuries from 1750 to 1950.
This period of rapid population growth in countries of European settlement
occurred largely because of a reduction in death rates, which was in turn due to
the nutritional improvements afforded by agricultural improvement.
Improvement in public sanitation followed and the practice of medicine also
started to have an effect.
After 1870, birth rates started to decline which slowed down European
The last period, which started around 1950 and will probably continue into the
first two decades of the twenty-first century, might be called the period of
Third World population expansion.
The decline in death rates served as a function of improved medicine,
improved living conditions and better sanitation.
After 1970, birth rates started to decline in the developing countries.
In both the European and Third World expansions, growth has occurred
because death rates fell sooner and faster than did birth rates.
The larger, more rapidly growing population has a significantly smaller share
of the worlds economic product.
The wealthy, smaller population wields power in the world.
John Maynard Keynes is the father of modern economics. He thought that big
historical events are often caused by slow demographic processes.
Apolitical economist who was the first to develop a systematic theory of
population change and its relation to economic conditions.
Due to the natural attraction between the sexes, along with what he called an
urge to reproduce, he thought there was a natural tendency for the
population to grow.
He saw two checks on population growth.
Positive checks occurred through mortality, from causes such as famine,
epidemics, wars and plagues.