Monday, 19 October 2009

More than 2 children?

Why it's SO important to have more than 2 children in a family.
If 2 sets of parents, each have one child, there are half as many children as parents.
If those children have one child, then there is 1/4 as many grandchildren as granparents.
And this means that the population of your nation is decreases.

Saturday, 17 October 2009

Basic demographic equation

Suppose that a country (or other entity) contains Populationt persons at time t.

What is the size of the population at time t + 1 ?
Populationt + 1 = Populationt + Naturalincreaset + Netmigrationt

Natural increase from time t to t + 1:
Natural Increaset = Birthst − Deathst

Net migration from time t to t + 1:
Netmigrationt = Immigrationt − Emigrationt

This basic equation can also be applied to subpopulations. For example, the population size of ethnic groups or nationalities within a given society or country is subject to the same sources of change. However, when dealing with ethnic groups, "net migration" might have to be subdivided into physical migration and ethnic reidentification (assimilation). Individuals who change their ethnic self-labels or whose ethnic classification in government statistics changes over time may be thought of as migrating or moving from one population subcategory to another.
More generally, while the basic demographic equation holds true by definition, in practice the recording and counting of events (births, deaths, immigration, emigration) and the enumeration of the total population size are subject to error. So allowance needs to be made for error in the underlying statistics when any accounting of population size or change is made.

Women's rights in Islam

Effort to improve the status of women in Islam occurred during the early reforms under Islam between 610 and 661, when women were given greater rights in marriage, divorce and inheritance.[1] In 622 the Constitution of Medina was drafted by the Islamic prophet Muhammad, outlining many of Muhammad's early reforms under Islam, including an improved legal status for women in Islam, who were generally given greater rights than women in pre-Islamic Arabia[1][2] and medieval Europe.[3] Women were not accorded with such legal status in other cultures until centuries later.[4]

[1] Esposito (2005) p. 79
[2] Majid Khadduri, Marriage in Islamic Law: The Modernist Viewpoints, American Journal of Comparative Law, Vol. 26, No. 2, pp. 213-218
[3] Encyclopedia of religion, second edition, Lindsay Jones, p.6224, ISBN 0-02-865742-X
[4] Lindsay Jones, p.6224