Intro14 Glob12.1: Demography

DEMOGRAPHY is the statistical study of living human populations. It encompasses the study of the size, structure, and distribution of these populations, and spatial and/or temporal changes in them in response to birth, migration, aging and death.

There is a number of key statistics (measurements) that can tell us a lot about a given society (country).

Total population is usually too general for most studies. We are often interested in age-specific, population, migration, and death rate in addition to total population, migration, and death rate.

The crude birth rate is the number of births per 1,000 people per year.

MORTALITY (DEATH) RATE

MORTALITY is the rate of deaths in a population over time.

More official and complex definition (from World Bank): FERTILITY RATE is “the number of children that would be born to a woman if she were to live to the end of her childbearing years and bear children in accordance with prevailing age-specific fertility rates.”

Fertility rates are more useful for predicting population change than (crude) birth rates, because it is unafected by the age structure of the population.

Birth rates (and RNI) focus on the present, while fertility rate talks about the future. In other words, birth/death rates and RNI tell you about the population's present, while fertility rate will tell you about it's future.

While all countries' population pyramids differ, four general types have been identified by the fertility and mortality rates of a country.

Population pyramid of South Korea is an example of a contacting (aging) pyramid

In poor societies, people presume that many babies will die, and large families are valued, as each surviving baby brings profit to the family, helping support the old.

As societies industrialize and modernize, people have fewer babies. New technologies (medicine, hygiene) decrease death rates. There is a lag between when the death rate declines and and the birth rate gong down; that's the population explosion.

Large families become a burden in non-agricultural work, people (especially women) pursue education and careers, and having a baby is increasingly seen as an expensive luxury, not a necessity.

Sex ratio should be 1:1 (for each male, there should be one female). If sex ratio is skewed, social tension can arise.

Sex ration can be skewed due to:

* old age (females tend to live longer) - this is not a problem for a society

* war (men tend to fight more and die more in war)

* female infanticide and selective abortions (in many cultures, males are valued more, which leads to abortions of female fetuses and killing of infants

Skewed sex ratio means that males cannot find girls to marry. This leads to crime - in particular, sexual violence (rapes), and bride import.

Sex ration at birth in Korea (female to male ratio) is 0.93, giving it the 121st rank in a worldwide ranking.

Chung and Gupta argue that South Korea is the trendsetter in many East Asian trends, and thus predict that China and India will follow the Korean model in improving their sex ratio.

Chung and Gupta find that "Son preference declines with increasing socioeconomic status, lower parental control, younger birth cohort, and older age at marriage. Buddhists show significantly higher son preference, as do women whose husbands are the only son, couples who live with their parents, and those whose marriages were arranged by their parents."

For more on sex ratio in Korea, read

Chung and Gupta (2007), "The Decline of Son Preference in South Korea: The Roles of Development and Public Policy" http://onlinelibrary.wiley.com/doi/10.1111/j.1728-4457.2007.00196.x/abstract

ETHNIC COMPOSITION is another important indicator, describing proportions of various ethnic subpopulations in a society.

If one ethnic subpopulation is growing while others are stable, this is likely to lead to ethnic tensions.

this is happening in much of Europe and USA

South Korea is among the world's most ethnically homogeneous nations, meaning 1) almost everyone speaks the same language and 2) there are very few foreigners living in South Korea.

Note that often ethnic groups are not recent migrants. Some of those groups might have lived in a given country for centuries (ex. Jews in various countries, African-Americans in the USA, etc.)

Ethnic diversification is common in Africa, where many countries were created from a number of different tribes

MIGRATION - movement of people into and out of a society

In the South Korean population of about 50 million, about 800,000 people are foreigner IMMIGRANTS.

IMMIGRATION: migration of people into society

EMIGRATION: movement of people out of society

Reasons for migration:

economic (modern: looking for job; historical: famine, population pressure)

political and cultural (refugees)

spouses (including "mail order brides")

forced migration and resettlement (such as in Europe after WWII)

By the end of 1988 there were over 2 million South Korean overseas residents. North America was the preferred destination, as the choice of over 1.2 million.

INTERNAL MIGRATION - movement within a given country. One of the most significant internal migrations occurred in recent centuries due to URBANIZATION - movement from the rural areas into the cities.

In some places there is a trend to reverse urbanization, as people try to move out of the cities into a less crowded countryside. This is helped particularly by TELECOMUTING - being able to work from one's home.

FERTILITY RATES are highest in the poor regions of the world

AGE-SPECIFIC date is very useful

Constrictive pyramid

A population pyramid that comes in at the bottom. The population is generally older on average, as the country has long life expectancy, a low death rate, but also a low birth rate. This pyramid is becoming more common, especially when immigrants are factored out, and is a typical pattern for a very developed country, a high level of education, easy access to and incentive to use birth control, good health care, and few negative environmental factors.

Stationary pyramid

A population pyramid typical of countries with low fertility and low mortality, very similar to a constrictive pyramid.

Stable pyramid

A population pyramid showing an unchanging pattern of fertility and mortality.

Expansive pyramid

A population pyramid that is very wide at the base, indicating high birth and death rates.

World population is stabilizing;

developed world is aging

5-9 years old

0-4 years old

Korea is aging rapidly

RATE OF NATURAL INCREASE

http://en.wikipedia.org/wiki/Demography

DEMOGRAPHY

SEX RATIO

FERTILITY RATE

“Demo” means “the people” and “graphy” means “measurement”

But keep in mind neither takes into account migration.

read more: http://en.wikipedia.org/wiki/Missing_women_of_Asia

Sex ratio in China is even more dire

How can we explain those relations?

Many sociologists are demographers, and others work with data made available by demographers, such as censuses.

BIRTH RATE

Ethnic composition and migration

The simplest demographical statistic about a given population is the total population - the number of people living in a given country.

some European countries, like Poland, are very similar to South Korea

Read more: http://en.wikipedia.org/wiki/Foreigners_in_Korea

http://en.wikipedia.org/wiki/Demographics_of_South_Korea

Videos for discussion

Hans Rosling looks at a a large number of trends, many demographic, changing the modern world

http://www.ted.com/talks/hans_rosling_at_state.html

Introduction to sociology

Demography