3. comes from “populous”, the Greek word for people.
is considered as both an influence on society and also
a phenomenon which is subject to social influence.
from the demographic point of view, it simply means
the number of people living in a given area.
WHAT IS POPULATION?
4. the science of population.
is defined as the study of the size, distribution,
composition and changes in population.
represents a fundamental approach to the understanding
of human society.
Is usually regarded as subdiscipline of sociology because
population dynamics are strongly affected by social factors.
WHAT IS DEMOGRAPHY?
5. There is no stable population. Some populations
increase and others decrease. The size of given population
may change rapidly while others may change much more
slowly. In some populations, there is a high proportion of
people under fifteen. Most population have more females
than males in the older generation. These and other
population characters are results of many factors which may
be biological, demographic, social, economic, political or
cultural.
DETERMINANTS OF DEMOGRAPHIC TRENDS
6. Population growth – means increase in the size of
population.
THE WORLD PICTURE
For over a million years, the growth of the world’s population was
negligible. It took mankind four million years to reach one billion in the early
1800’s. From 1804, when the world passed the 1 billion mark, it took 124 years
to reach 2 billion. We entered the end of the 20th century with a population of
less than 2 billion. And towards the end of this century, the world population
reached 6 billion. The United Nations Population Fund (UNPF) designated
October 12, 1999, as the “Day of 6 Billion”.
7. THE PHILIPPINE SITUATION
The Philippine is one of the fastest-
growing countries in the world. It is the 13th
most populous country, the 8th in Asia and
the third in Southeast Asia. In territorial size,
the Philippines ranks 56th in the world and
13th in Asia. The Philippines contains 1
percent of the world’s population and 1.8
percent of Asia’s population. The growth of
the Philippine population from 1903 to 2010
is shown in the table. (Source: National
Statistic Reports, various years)
9. FERTILITY
a demographic phenomenon greatly responsible for
setting population trends.
means that a woman has actually given birth to a live
child.
It tells how many children the average woman is
bearing.
Fertility is actual reproduction, whereas fecundity is
potential reproduction.
10. Demographers have developed several
methods to measure fertility:
o Crude Birth Rate (CBR) – computed by dividing the
number of live births during a calendar year to the
midyear population of the same period, expressed per
1,000 population.
o General Fertility Rate (GFR) – more refined measure
of fertility; the number of births occurring in a calendar
year to 1,000 women of childbearing ages (15-49).
12. Factor influencing fertility differentials:
Education. The higher the educational attainment, especially that of a woman, the
lower is the number of children.
Occupation of the father and income. Fathers of high paying occupations have fewer
children.
Rural-Urban Differential. Fertility is higher in rural areas. The difference is probably
due to the fact that the rural couples cannot readily get information and facilities for
family planning.
Age at marriage. Delayed marriage means lesser exposure to fertility and therefore
reduces the number of children born to a woman.
Ambition. Ambition is the desire to maintain or to secure a good social status. For
many couples with good social status, it is easier to maintain that status and ensure the
same status to their children if families are relatively small.
13. MORTALITY
refers to death.
It is a negative component of population change.
Is an indicator of health conditions of a given society.
14. Measures of mortality:
Crude Death Rate (CDR) – the number of deaths per 1,000 population.
Age-Specific Death Rate – the number of deaths of persons in a given age-
group per 1,000 population of that age-group.
Infant Mortality Rate (IMR) – computed by dividing the total number of
deaths of age 0 by the total population of the same age; it is expressed as the
number of infant deaths per 1,000 live births; it indicates how many babies die
before reaching the age one.
Death Rate by Cause of Death – commonly expressed in terms of death
from a given country expressed in terms of deaths from a given disease (cause
of death) per 1,000 population.
Maternal Mortality Rate – states the number of mothers dying per 1,000 live
births.
15. MIGRATION
The movement of people from one area to another
to settle permanently.
Two General Kinds of Migration
International Migration
Internal Migration
16. International Migration – the movement of people from
one country to another to settle permanently.
Immigration – the coming into the country of
which the person is not a citizen for permanent
residence.
Emigration – the going from one’s country for
permanent residence in another country.
17. Internal Migration – the movement of people from one
part of the country to another for permanent residence.
Internal migration may be out-migration or in-migration.
18. Age Composition –refers to the relative proportions of people at
various age levels. The proportions in the different age groups
(children, adults, aged) vary greatly from time to time and from
society to society. Data on a population’s age structure provide a
basis of varies demographic analysis which may lead to an
approximation of the characteristics of the future population.
Sex Composition – refers to the differences in sex-make up
which is determined by sex ratio (the proportion of males over
females).
POPULATION STRUCTURE: Age and sex Composition