Changes

==Demography==

==Demography==

In [[Demography]], fertility is the statistical analysis of having babies.  Couples do it, and so too do entire societies, in a way. Therefore demographers approach the topic at both the individual and the social level. At the individual level, the statistics are normally analyzed in terms of the mother, though admittedly the father plays a role as well. At the social level we measure fertility with different rates using birth statistics and census data. Research on fertility inside the United States has slowed in recent decades, because most of the important questions have been answered. nearly identical. There has been a shift from a focus on fertility as the basis of population growth to one of fertility as a component of health, marital and family-building patterns, and the connection to women's employment and careerism. There has been new attention to racial and ethnic patterns, and to the fertility of unmarried women. Attention has shifted to historical patterns in the US and Europe, going back to the year 1600. Even more important, attention has shifted to the rapid growth of population in developing countries, especially in Asia, Africa and Latin America. In terms of world population, the main issue is the overall number of births, and how it can be reduced.  

In [[Demography]], fertility is the statistical analysis of having babies.  Couples do it, and so too do entire societies, in a way. Therefore, demographers approach the topic at both the individual and the social level. At the individual level, the statistics are normally analyzed in terms of the mother, though admittedly the father plays a role as well. At the social level we measure fertility with different rates using birth statistics and census data. Research on fertility inside the United States has slowed in recent decades, because most of the important questions have been answered. nearly identical. There has been a shift from a focus on fertility as the basis of population growth to one of fertility as a component of health, marital and family-building patterns, and the connection to women's employment and careerism. There has been new attention to racial and ethnic patterns, and to the fertility of unmarried women. Attention has shifted to historical patterns in the US and Europe, going back to the year 1600. Even more important, attention has shifted to the rapid growth of population in developing countries, especially in Asia, Africa and Latin America. In terms of world population, the main issue is the overall number of births, and how it can be reduced.  

==Measuring Fertility==

==Measuring Fertility==

===Period Measures===

===Period Measures===

"Period" measures refer to a cross-section of the population in one year. "Cohort" data on the other hand, follows the same people over a period of decades. Both period and cohort measures are widely used.   

"Period" measures refer to a cross-section of the population in one year. "Cohort" data on the other hand, follows the same people over a period of decades. Both period and cohort measures are widely used.   

*'''[[Crude Birth Rate]]'''. The CBR is simply the number of births in a year divided by the midyear population, times 1000. Since 1972, the CBR for the USA has been fairly steady , between 14.0 and 16.0. To calculate it you need to count the number of births and know how large the population is.   

*'''[[Crude Birth Rate]]'''. The CBR is simply the number of births in a year divided by the midyear population, times 1000. Since 1972, the CBR for the USA has been fairly steady, between 14.0 and 16.0. To calculate it you need to count the number of births and know how large the population is.   

*'''[[General Fertility Rate]]'''. GFR is the number of births in a year divided by the number of women aged 15–44, times 1000. It focuses on the potential mothers only, and takes the age distribution into account. To calculate it you need age data.   

*'''[[General Fertility Rate]]'''. GFR is the number of births in a year divided by the number of women aged 15–44, times 1000. It focuses on the potential mothers only, and takes the age distribution into account. To calculate it you need age data.   

*'''Child-Woman Ratio'''. CWR equals ratio of the number of children under 5 to the number of women 15-49, times 1000. It is especially useful in historical data. It does not require counting births. This measure is actually a hybrid, because it involves deaths as well as births. (That is, because of infant mortality some of the births are not included; and because of adult mortality, some of the women who gave birth are not counted either.)   

*'''Child-Woman Ratio'''. CWR equals ratio of the number of children under 5 to the number of women 15-49, times 1000. It is especially useful in historical data. It does not require counting births. This measure is actually a hybrid, because it involves deaths as well as births. (That is, because of infant mortality some of the births are not included; and because of adult mortality, some of the women who gave birth are not counted either.)   

*'''[[Coale's Index of Fertility]]''' is a special device used in historical reseach.

*'''[[Coale's Index of Fertility]]''' is a special device used in historical research.

===Cohort Measures===

===Cohort Measures===

===Biological Determinants.===

===Biological Determinants.===

"Fecundity" is the biological ability to have children, It is a function of age, health and nutrition. Fecundity begins at menarche, is low for several years and then increases quickly to a maximum in the early 20s, then declines to menopause (about age 50). "Natural fertility" is the level of fertility reached without any form of conscious birth control. The [[Hutterites]], a small religious group in the U.S. and Canada who resemble the better-known Amish, do not practice birth control. Therefore their fertility pattern is used as a statistical model of "natural fertility" for a population that does not use any contraception. Hutterite women average 12 children each.   

"Fecundity" is the biological ability to have children, It is a function of age, health and nutrition. Fecundity begins at menarche, is low for several years and then increases quickly to a maximum in the early 20s, then declines to menopause (about age 50). "Natural fertility" is the level of fertility reached without any form of conscious birth control. The [[Hutterites]], a small religious group in the U.S. and Canada who resemble the better-known Amish, do not practice birth control. Therefore, their fertility pattern is used as a statistical model of "natural fertility" for a population that does not use any contraception. Hutterite women average 12 children each.   

===Social Components of Fertility.===

===Social Components of Fertility.===

==High Fertility Countries: India, Ghana, Jordan==

==High Fertility Countries: India, Ghana, Jordan==

The need to replenish society is a major cause of high fertilty. Before World War Two, mortality was so high in India that they needed the very high CBR of 37 (37 births a year per 1000 population) just to stay even (ie to keep a NRR of 1.0). In addition there was a strong commitment to the idea of the lineage. Everyone had a duty to ancestors and descendants to keep the line going, and indeed to maximize its strength or numbers. Thus there was a demand for high fertility.   

The need to replenish society is a major cause of high fertility. Before World War Two, mortality was so high in India that they needed the very high CBR of 37 (37 births a year per 1000 population) just to stay even (i.e. to keep a NRR of 1.0). In addition there was a strong commitment to the idea of the lineage. Everyone had a duty to ancestors and descendants to keep the line going, and indeed to maximize its strength or numbers. Thus there was a demand for high fertility.   

Sometimes, a minority group will promote high fertility in order to gain relative power, as for example the Palestinians in Jordan today (vis-a-vis Israel), and a century ago, the French (vis-a-vis Germany).   

Sometimes, a minority group will promote high fertility in order to gain relative power, as for example the Palestinians in Jordan today (vis-a-vis Israel), and a century ago, the French (vis-a-vis Germany).