DEMOGRAPHY

Demography – is the scientific study of population. - Greek word “demos” and “ Graphone” means measuring people. - studies the size and consistency of the human population and how it change

Population-area of sociology that includes the size, growth, demographic characteristics, composition, migration, changes, and the quality of vis-à-vis economic, political and social system. (zulueta,2002)- number of persons occupying a certain geographic area, drawing subsistence from their habitat and interacting with one another.

WHY STUDY POPULATION?

Population is important to habituate the earth and make use of its reasources Constant increase of population poses a threat to man’s subsistence

(Balliao and Loriega 1999) any significant increase or decrease of population size and growth rates may affect or even disrupt social life.

Population that grows too slowly faces the danger of extinction and population that grows too large may result to mass migration, cultural diffusion, or even worse displacing population in other territories.

( Schaeffer and Lamm, 1992) issues such as overpopulation, subfecundity, and immigration are important because they help shape the quality of life in our society and on the planet as a whole.

SOURCES OF DEMOGRAPHIC DATA

1. Census – population count where the demographic, economic, and social data of individual of a given time are collected, tabulated, compiled and published. -- National Statistics Office ( NSO) Under Commonwealth Act No. 591

2. Vital Statistic System – Events that deal with an individual life from birth to death and those in between such as marriage, annulments, adoptions, separations, divorce. - Republic Act 3753 or the Civil Registry Law of the Philippines

3. Sample Surveys – conducted by private and pubic institutions to obtain data and information on matters not covered by the census or the vital statistics system.

Composition Of A Population

- Pertains to the characteristics of individuals being studied like age, sex, civil status, race or ethnicity, and education when measure as groups.

1. Age Composition - the comparative percentage of individuals at different age levels influencing the economic and social structure of the society.

2. Sex Composition – the gender differences which is determined by sex ratio ( proportion of males over females per 100 population) affected by birth, death, and migration.

Population Pyramid or Age-Sex Pyramid - also known as Tree of Ages. Presents the age and sex characteristics of a population which can be used as prediction of its growth and decline.

Elements of Demography

1. Birthrate - The yearly count of live births per 1000 population; gives data on a society’s reproductive pattern

2. Total Fertility Rate- The average count of children cncieved; can project a society’s future population growth.

3.Deathrate - the yearly count of depths per 1000 population; gives date on mortality patterns.

4. Life Expectancy- the average number of years a person is expected to live.

5. Growth rate- differences between births and deaths plus differences between immigrants and emigrants.

THE REV. THOMAS ROBERT MALTHUS: PRINCIPLE OF POPULATION

Rev. Thomas Robert Malthus – English clergyman and college professor - publish the “Principle of Population” (1780) which was the first important contribution to the study of population. - Proposed the postponement of marriage as a means of population

conrol which is consider as the answer to the widening gap between population and food supply.

Karl Marx- Saw no significant relationship between population and food - He criticized Malthus’ view on population arguing that capitalism is the cause of social ills.

PAUL EHRLICH: The population Bomb

PAUL EHRLICH- author of the “Population Bomb” Proponent of the neo- Malthusian theory which espoused that the sensible use of the world’s resources and birth control are the factors to consider in population growth.

Worlds Population Situation:

Pessimistic and Optimistic views on population.

Robert Malthus – 18th century express his optimistic view of runaway population and inadequate food supply.

OPTIMISTIC VIEW; - over population is a a myth and not a problem. - Population growth is essential for long term economic growth. Bigger population is a bigger potential for strong defense against invasion.

SCIENCE:- human being have been on this earth for about 1 million to 2 million years.- Neolitjic stage: population increased 10 million; death and birth is balance - 1974 population increased by 4 million- 1980 population increased by 4.4 million - 1987 population increased by 5 million- 1990 population reached 5.2 billion

World Almanac for kids- recorded the 1998 population of the world’s largest countries.

Demographic Transition- used in population trend syudes, pertains to be observed pattern in changing vital statistics (Birth rates and Death Rates)

Stages of Demographic Transition

1.Pretransition stage - first stage occur in 18th century - characterized by high birth and death rateswith minimal population growth.

2.Transition Stage - took place in 18th to 19th centuries. - Stage of declining death rate and it was the era of Industrial Revolution and Population Explosion.

3.Posttransition Stage - took place in late 19th century - characterized by low birth and death rates with minimal population growth.

World War II – Asia, Africa, Latin America experiencing population explosion, low death rate and stable fertility rates.

Green Revolution- increased in food production and improve public health care. - Infant mortality declined and life expectancy increased.

PHILIPPINE POPULATION SITUATION

World Almanac for Kids. 1998 – 77, 726, 000 population

National Statistic Office1998 – 75, 155, 00 population

CAUSES OF RAPID POPULATION GROWTH

1. Birth Rate – more than 4 babies are born in second. - there is a natural urge for people to reproduce and the population has a constant tendency to increase. - directly affected by Fertility

2. Death Rate – Mortality has drop because of modern and ore expensive medical discoveries, vaccination services, better nutrition and enhanced sanitation.- Death are reamined unrecorded- Crude death rate can still obtained based on recorded number of death per year multiplied by 1000.

3. Migration- movement of people from one place to another with the intention of finding a permanent residence.

Theory of Imagination – explain the reason why people transfer residence -Push factor Family push away from their homes due to natural calamities.-Pull Factor -promises and extensive opportunities for a better life.

Consequence of Rapid Population Growth

1. Economic Consequence - slows down the growth capita income tends tends to perpetuate inequalities in income ditribution.