Editing Demographic transition (section)

===Stage three===
[[File:Uzbekistan population pyramid.svg|thumb|Population pyramid of [[Demographics of Uzbekistan|Uzbekistan]] in 2023 (Stage three).]]
[[File:Israel_2023_Population_Pyramid.svg|thumb|Population pyramid of [[Demographics of Israel|Israel]] in 2023 (Stage three).]]

In Stage 3 of the Demographic Transition Model (DTM), death rates are low and birth rates diminish, as a rule accordingly of enhanced economic conditions, an expansion in women's status and education, and access to contraception. The decrease in birth rate fluctuates from nation to nation, as does the time span in which it is experienced.<ref>{{cite web|url=https://www.populationeducation.org/content/stage-3-demographic-transition-model|title=Stage 3 of the Demographic Transition Model - Population Education|date=16 October 2014}}</ref> Stage Three moves the population towards stability through a decline in the birth rate.<ref>{{Citation | publisher = UWC | url = http://pages.uwc.edu/keith.montgomery/Demotrans/demtran.htm | series = Marathon | title = Geography | contribution = Demographic transition | access-date = 2014-04-25 | archive-date = 2019-06-05 | archive-url = https://web.archive.org/web/20190605095831/http://pages.uwc.edu/keith.montgomery/demotrans/demtran.htm | url-status = dead }}.</ref> Several [[fertility factor (demography)|fertility factor]]s contribute to this eventual decline, and are generally similar to [[Sub-replacement fertility#Causes|those associated with sub-replacement fertility]], although some are speculative:
* In rural areas continued decline in childhood death meant that at some point parents realized that they did not need as many children to ensure a comfortable old age. As childhood death continues to fall and incomes increase, parents can become increasingly confident that fewer children will suffice to help in family business and care for them at old age.
* Increasing [[urbanization]] changes the traditional values placed upon fertility and the value of children in rural society. Urban living also raises the cost of dependent children to a family. A recent theory suggests that urbanization also contributes to reducing the birth rate because it disrupts optimal mating patterns. A 2008 study in Iceland found that the most fecund marriages are between distant cousins. Genetic incompatibilities inherent in more distant out breeding makes reproduction harder.<ref>{{Citation | title= Third Cousins Have Greatest Number Of Offspring, Data From Iceland Shows | url= https://www.sciencedaily.com/releases/2008/02/080207140855.htm | archive-url= https://web.archive.org/web/20210102112300/https://www.sciencedaily.com/releases/2008/02/080207140855.htm | url-status= dead | archive-date= 2 January 2021 | journal= ScienceDaily | date = 8 February 2008}}.</ref>
* In both rural and urban areas, the cost of children to parents is exacerbated by the introduction of compulsory education acts and the increased need to educate children so they can take up a respected position in society. Children are increasingly prohibited under law from working outside the household and make an increasingly limited contribution to the household, as school children are increasingly exempted from the expectation of making a significant contribution to domestic work. Even in equatorial Africa, children (under the age of 5) are now required to have clothes and shoes, and may even need school uniforms. Parents begin to consider it a duty to buy children's books and toys. Partly due to education and access to family planning, people begin to reassess their need for children and their ability to raise them.<ref name=Caldwell5/>
[[File:Familyplanningmalaysia.jpg|thumb|right|upright=1.15|A major factor in reducing birth rates in stage&nbsp;3 countries such as Malaysia is the availability of family planning facilities, like this one in Kuala Terengganu, Terengganu, Malaysia.]]
* Increasing literacy and employment lowers the uncritical acceptance of childbearing and motherhood as measures of the status of women. Working women have less time to raise children; this is particularly an issue where fathers traditionally make little or no contribution to child-raising, such as [[southern Europe]] or [[Japan]]. Valuation of women beyond childbearing and motherhood becomes important.
* Improvements in contraceptive technology are now a major factor in fertility decline. Changes in values regarding children and gender play as significant a role as the availability of contraceptives and knowledge of how to use them.

The resulting changes in the age structure of the population include a decline in the youth [[dependency ratio]] and eventually [[population aging]]. The population structure becomes less triangular and more like an elongated balloon. During the period between the decline in youth dependency and rise in old age dependency there is a [[demographic window]] of opportunity that can potentially produce economic growth through an increase in the ratio of working age to dependent population; the [[demographic dividend]].

However, unless factors such as those listed above are allowed to work, a society's birth rates may not drop to a low level in due time, which means that the society cannot proceed to stage three and is locked in what is called a [[demographic trap]].

Countries that have witnessed a fertility decline of over 50% from their pre-transition levels include: [[Costa Rica]], [[El Salvador]], [[Panama]], [[Jamaica]], [[Mexico]], [[Colombia]], [[Ecuador]], [[Guyana]], [[Philippines]], [[Indonesia]], [[Malaysia]], [[Sri Lanka]], [[Turkey]], [[Azerbaijan]], [[Turkmenistan]], [[Uzbekistan]], [[Tunisia]], [[Algeria]], [[Morocco]], [[Lebanon]], [[South Africa]], [[India]], [[Saudi Arabia]], and many [[Pacific islands]].

Countries that have experienced a fertility decline of 25–50% include: [[Demographics of Guatemala|Guatemala]], [[Demographics of Tajikistan|Tajikistan]], [[Demographics of Egypt|Egypt]] and [[Demographics of Zimbabwe|Zimbabwe]].

Countries that have experienced a fertility decline of less than 25% include: [[Demographics of Sudan|Sudan]], [[Demographics of Niger|Niger]], [[Demographics of Afghanistan|Afghanistan]].