La moral y los valores vistos por los niños y adolescentes

Demography relies on large data sets that are primarily derived from censuses⁷ and registration statistics (i.e., birth, death, marriage registrations). Large data sets over long periods of time (e.g., the U.S. census is conducted every 10 years) are required to develop trends in demographic indicators, like birth and death rates.

In many countries, particularly in developing nations, reliable demographic data are still difficult to obtain. In some locales this may be due to the association ofcensuswithtaxation.

15.4.1 Demographic Indicators

Because demography is interested in changes in human populations, demographers focus on specific indicators of change. Two of the most important indicators are birth and death rates, which are also referred to asfertility⁸(see also fecundity⁹) andmortality. Additionally, demographers are interested in migration trends or the movement of people from one location to another. Some of the specific measures used to explore these elements of population change are discussed below.

15.4.2 Fertility and Fecundity

Fertility, in demography, refers to the ability of females to produce healthy offspring in abundance.

Fecundityis the potential reproductive capacity of a female. Some of the more common demographic measures used in relation to fertility and/or fecundity include:

• crude birth rate: the annual number of live births per thousand people

• general fertility rate: the annual number of live births per 1000 women of childbearing age (often taken to be from 15 to 49 years old, but sometimes from 15 to 44).

• age-specific fertility rate: the annual number of live births per 1000 women in particular age groups (usually age 15-19, 20-24 etc.)

• total fertility rate: the number of live births per woman completing her reproductive life if her childbearing at each age reflected current age-specific fertility rates

• gross reproduction rate: the number of daughters who would be born to a woman completing her reproductive life at current age-specific fertility rates

• net reproduction rate: the number of daughters who would be born to a woman according to current age-specific fertility and mortality rates

7 http://en.wikipedia.org/wiki/census 8 http://en.wikipedia.org/wiki/fertility 9 http://en.wikipedia.org/wiki/fecundity

Data and Methods Another important demographic concept relating to fertility is replacement level. Replacement level fertility refers to the number of children that a woman (or monogamous couple) must have in order to replace the existing population. Sub-replacement fertility is a fertility rate that is not high enough to replace an existing population. Replacement level fertility is generally set at 2.1 children in a woman's lifetime (this number varies by geographic region given different mortality rates). Sub-replacement fertility is below approximately 2.1 children in a woman's life time. The reason the number is set to 2.1 children per woman is because two children are needed to replace the parents and an additional one-tenth of a child is needed to make up for the mortality of children and women who do not reach the end of their reproductive years.¹⁰ Of course, women don't have one-tenth of a child; this results from statistical averaging between women who have more than two children and those who have two or fewer children.

The chart below illustrates trends in childbearing by region of the world. Fertility rates dropped earlier in the more developed regions of the world, followed by Asia and Latin America. Fertility rates are just starting to decline in Africa.

Figure 38

The chart below highlights the varied fertility rates of specific countries as some have very low fertility rates, many have moderate rates, and some have very high rates.

10 carr, deborah. 2009. “worries over a population implosion.” Contexts 8:58-59.

Figure 39

The following chart illustrates the relationship between contraceptive use and the total fertility rate by regions of the world. Increased contraceptive use is associated with lower numbers of children per woman.

Figure 40

Data and Methods One of the strongest predictors of fertility rates is women's educational attainment¹¹.¹² Almost universally, higher levels of educational attainment result in lower fertility rates. It is not, however, education itself that causes declines in fertility but rather its association with other factors that reduce fertility: women with higher levels of education delay marriage, have improved labor market opportunities, are more likely to use contraception¹³during intercourse, and are less likely to adopt traditional childbearing roles.¹⁴

Fertility rates are also closely related to a country's level of development, which influences other factors.¹⁵ For instance, women who have kids in developed countries have increased opportunity costs, meaning they will make less money because of time spent outside the workforce raising kids.

This is true in developed countries because women are more likely to be highly skilled and well-paid (relative to women in developing countries). Additionally, delayed childbearing, probability of a child reaching adulthood, norms about ideal family sizes, and pervasiveness of contraceptives will all reduce fertility rates. But one of the biggest factors is the cost of children. In undeveloped and developing countries, children are often an economic asset to parents as they serve as cheap labor on the farm; they don't require pay, just food and shelter. That is not the case in developed countries, where very few people work in agriculture (roughly 2% in the US). Instead, children are an economic liability, meaning they cost money while not generating money for the parents. The cost of raising a child from birth to 17 in a middle-income home in 2005 was $191,000.¹⁶That cost goes up if parents pay for a child's college education, which averages between $12,000 and $30,000. Thus, the cost of raising children in developed countries reduces fertility rates in those countries.¹⁷

15.4.3 Mortality

Mortalityrefers to the finite nature of humanity: people die. Mortality in demography is interested in the number of deaths in a given time or place or the proportion of deaths in relation to a population.

Some of the more common demographic measures of mortality include:

• crude death rate: the annual number of deaths per 1000 people

• infant mortality rate: the annual number of deaths of children less than 1 year old per thousand live births

• life expectancy: the number of years which an individual at a given age can expect to live at present mortality rates

Note that the crude death rate as defined above and applied to a whole population can give a misleading impression. For example, the number of deaths per 1000 people can be higher for developed nations than in less-developed countries, despite standards of health being better in developed countries. This is because developed countries have relatively more older people, who are more likely to die in a given year, so that the overall mortality rate can be higher even if the mortality

11 http://en.wikibooks.org/wiki/Introduction_to_Sociology%2FEducation

12 Mare, R.D., & Maralani, V. (2006). The Intergenerational Effects of Changes in Women's Educational Attainments.

American Sociological Review, 71(4), 542-564.

13 http://en.wikipedia.org/wiki/contraception

14 Mare, R.D., & Maralani, V. (2006). The Intergenerational Effects of Changes in Women's Educational Attainments.

American Sociological Review, 71(4), 542-564.

15 carr, deborah. 2007. “the cost of kids.” Contexts 6:62.

16 carr, deborah. 2007. “the cost of kids.” Contexts 6:62.

17 carr, deborah. 2007. “the cost of kids.” Contexts 6:62.

rate at any given age is lower. A more complete picture of mortality is given by a life table¹⁸which summarizes mortality separately at each age.

This chart depicts infant mortality by region of the world. The less developed regions of the world have higher infant mortality rates than the more developed regions.

Figure 41

This chart depicts life expectancy by region of the world. Similar to infant mortality, life expectancies are higher in more developed regions of the world.

18 http://en.wikipedia.org/wiki/Life%20table

Data and Methods

Figure 42

According to recent research,¹⁹one of the best predictors of longevity²⁰(i.e., a long life) is education, even when other factors are controlled: the more educated you are, the longer you can expect to live.

A few additional years of schooling can add several additional years to your life and vastly improve your health in old age. The mechanism through which this works is not the schooling itself, but schooling's influence on other health-related behaviors. The more education someone has, the lower his/her likelihood of smoking and engaging in unhealthy and high risk behaviors. Education also increases the probability of people engaging in healthy behaviors, like frequently exercising.²¹ Other factors associated with greater longevity include:

• wealth: money increases access to good healthcare, which improves health and increases longevity

• race: whites live longer than blacks, though this is due to other social disparities, like income and education, and not to race itself

• ability to delay gratification: with the ability to delay gratification people live healthier lives and engage in healthier behaviors (e.g., exercise)

• larger social networks: having a large group of friends and close relationships with relatives increases your social support²², which positively influences health

19 Kolata, G. (2007). A Surprising Secret to a Long Life: Stay in School. The New York Times. Retrieved January 3, 2007.http://www.nytimes.com/2007/01/03/health/03aging.html

20 http://en.wikipedia.org/wiki/longevity

21 Kolata, G. (2007). A Surprising Secret to a Long Life: Stay in School. The New York Times. Retrieved January 3, 2007.http://www.nytimes.com/2007/01/03/health/03aging.html

22 http://en.wikipedia.org/wiki/social%20support

• job satisfaction: people in more powerful and more satisfying jobs tend to be healthier than people in less satisfying jobs