age and sex structure demography....pptx

public health notes

1. DEMOGRAPHIC AGE AND SEX CHARACTERISTICS. BY GROUP 4 10 TH MARCH, 2024. 1

2. 2 GROUP MEMBERS STUDENT ID NUMBERS Yahya Mbwana Mselem SID 178-960 Kirabo Faith 206-268 Offong Emem Eno 203-940 Oiye Ivan Etoku 208-014 Tausi Yunge 202-045 Wende Mlonganile 202-991 Buay Gatluak Ngep 202-881 Moses Richard Morris 203-334

3. Introduction Age and sex are the most important and relevant characteristics of population for demographers. The United Nation defines age as the interval of time between the date of birth and the date of consensus, expressed in complete solar years Sex refers to the fundamental characteristics of human populations based on biological attributes and distinguishes between females and males in a population. 3

4. Composition of age and sex The age distribution conveys the relative numbers of children, young and old as well as the balance between men and women at different ages. Almost all population characteristics vary significantly with age, as a component of population analysis, most of the analysis is based on the age and sex structure of the population. 4

5. Age structure Age structure of a population, refers to the number of people in different age groups in a country and it constitutes an important subject of demographic analysis and development planning. Demographers use some basic techniques for describing age and sex structure Frequency distribution Percentage distribution Ratios Bar graph Basic graphical tools Graphical analysis Population pyramids Graphical cohort analysis 5

6. Age structure is a important indicator of population composition, a large size of population in age group of 15-59 years, indicates a large working population hence requires more expenditure on health care facilities, also would mean that there is higher birth rate and population is youthful. A large percent of the dependent population tends to reduce savings and investment, the rate of economics and social advancement since most resources are being diverted towards consumptions. Age structure 6

7. Age Structure (Past, Present and Future) 7

8. Sex structure Sex structure of a population, refers to the number of males and females in a given population. The demographers often describes the sex composition of population by comparing the number of person of each sex with a ratio. The sex ratio, is the number of men divided by the number of women multiplied by a constant 100% =(men/women)*100 Sex ratios can be computed not only for total populations but also for classes within those populations , demographers frequently find it helpful to pay attention to sex composition at different age levels. 8

9. Sex pattern It shows to be constants in most countries, usually the highest at birth, about 102 to 105 males per 100 females. But the probability of dying at birth is higher for male children. Sex ratio is almost even in early adult years but decreases further in early old age, as the population age, the ratio reduces as the life expectancy is on average 3-5 years higher for females. Studies shows that men mature slower and die earlier than women. 9

10. Sex Ratio by Countries 10

11. Age and sex pyramid Refers to the number of females and males in different age groups. A population pyramid is used to show the age-sex structure of the population. The shape of the pyramid reflects the characteristics of the population. Age structural dynamics includes fertility, mortality and as well as related family planning and social arrangements. Public policies aim at improving the welfare of a population, where as the population welfare is shaped by the needs of present and future generation. 11

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14. Population pyramid A population pyramid is a graphic representation of the distribution (f) of a population by age and sex. The width represents the size of the population of the given age, women on the right and men on the left The bottom layer represents the number of newborns and above it the number of the older cohort Population pyramid is the basic procedure for assessing the quality of census data on age and sex The base of the pyramid is mainly determined by the level of fertility in the population. At the same time, how fast it converges to the peak is determined by previous levels of mortality and fertility as well as migrations. 14

15. EXAMPLE OF A POPULATION PYRAMID BY AGE- SEX STRUCTURE 15

16. Average age and dependency ratio Average age and dependency ratio are the two measures can help summarize an age structure in a few number, average age is generally calculated as the median, which measure the age above which is found half of the population and below which is the other half. Dependency ratio, is an index that is commonly used to measure the social and economic impact of different age structures, which is the ratio of the dependent age(the young and the old) to the working age population. The higher the ratio, the more people each potential worker is having to support, conversely the lower it is the fewer people there are dependent on each worker. Thus, dependency ratio does not capture all the intricacies of the age structure, but it is useful indicators of the burden that some age structure place on a population. 16

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19. Age and sex transition Premodern society will have high fertility ,high mortality and most probably little in or out of migration, this is associated with a young population, where as the end of the transition is associated with an older population characterized by low fertility, low mortality and probably moderate amount of immigration. This transition from a younger to an older population progresses through some predictable stages, with reasonably predictable consequences for the fabric of social life. 19

20. Factors affecting age and sex composition Birth rates; higher birth rates lead to a higher proportion of young people in the population, while lower rates result in an older population rate. Mortality rates; higher mortality rates decrease in the number of older while lower mortality rates result larger proportion of elderly in the population. Migration; can affect the age and sex composition of a population. For example, a country that a large number of young immigrants may have a younger population compared to a country with a higher emigration rate of young people. 20

21. Social and cultural factors; social norms, traditions and cultural practices influence fertility rates at marriage which in turn affect the age structure of a population. Economic factors, impacts rates and migration patterns which in turn influence the age and sex composition of a population Health care and access to healthcare; improved healthcare and access to health services can lead to lower mortality rates and longer life expectancy, resulting in an older population. War and conflict; events such as war and conflict may result in higher mortality rates particularly among young men, this can affect the sex composition of a population. Government policies ; such as family planning programs ,immigration Policies an etc. Factors affecting age and sex composition 21

22. Determinants of age and sex in the population Birth rates Mortality rates Migration 22

23. Importance of age sex structure Planning process Health services Education programs Labor supply Demographic study and research purpose for science and economist. Study population dynamics/patterns Fertility Mortality Migration Insight of quality of census enumeration 23

24. Contrast between more developed and less developed countries. Age structure Less developed regions have a higher proportion of a young population (<15 years), whereas more developed countries generally have a higher proportion of age population(=>65 year) In countries such as Latin America and the Caribbean, Asia, and North America the percentage under the age of fifteen falls in a closer range from higher to lower, while Europe has a greater older age than in younger ages. 24

25. In less developed regions, the population pyramid is almost symmetrical with little change, whereas more developed regions has a remarkable female lean/ as it rises to the older categories. In most regions men are slightly pre-dominant in the earliest ages, while women tend to outnumber men as they age, creating a female predominance especially in more developed countries. Sex structure 25

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27. Limitation in age and sex demographic characteristics Static Snapshot : A population pyramid displays the distribution of various age groups in a population at a specific point in time. It does not reflect changes or population dynamics over time, such as migration patterns, birth, and death rates, that can alter the structure significantly. Lack of Detail: While age-sex pyramids show broad age categories and the sex ratio, they do not provide information on marital status, race, ethnicity, or socio-economic status, which are important factors in demographic analysis. Hidden Inequalities : The age-sex structure might not reveal gender inequality issues, such as differences in education, employment, healthcare access, or political representation. Data Quality and Availability: The accuracy of a population pyramid depends on the quality of the census data it's based on. Age misreporting remains as the leading problem during censuses. 27

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