Age composition A population is characterized by the ratio of age groups that differ from each other in relation to reproduction. Age differences in a population significantly increase its ecological heterogeneity and, therefore, provide unequal resistance to the environment. As a result, the probability increases that in case of strong deviations from the norm, at least some viable individuals remain in the population and it will be able to continue its existence. The age composition of the population is adaptive. It is formed on the basis biological properties species, but always also reflects the strength of the influence of environmental factors. The age composition of a population affects both fertility and mortality in this moment, i.e. determines its ability to reproduce and shows what can be expected in the future.
In modular and unitary organisms, the age composition is significantly different. Age composition of modular
Let's look at organisms using plants as an example. In them, the age composition of cenopopulations is determined by the ratio of age groups, which are distinguished according to the age status of individuals. The absolute, or calendar, age of a plant and its age state are not identical concepts. Plants of the same calendar age can be in different age states. The age state of an individual is a stage of ontogenesis or life cycle. The following age groups are distinguished in plants:
sprouts - p;
juveniles - j;
immature individuals - im;
virgin individuals - v;
young generative individuals - gt;
middle-aged generative individuals - g2;
old generative individuals - g3;
subsenile individuals - ss;
senile individuals - s;
dying individuals - d.
Now we will describe in more detail the characteristics of each age group.
Seedlings are small plants with mixed type nutrition and embryonic structures. The seedling, as a rule, is a uniaxial shoot with small leaves.
Juveniles are plants with self catering, cotyledons are absent, but the organization is still simple, the leaves are smaller than those of adult individuals, and uniaxiality is maintained.
Immature individuals are transitional form plants to adult vegetative individuals, branching begins, and the photosynthetic apparatus increases.
Virgin individuals are adult vegetative plants with typical features life form, correspond to the generative state, but generative organs are absent.
Young generative individuals are plants that bloom, but have breaks in flowering, form fruits,
they undergo morphogenesis, accompanied by deep internal biochemical and physiological restructuring body.
Middle-aged generative individuals are plants that achieve the greatest annual growth and seed productivity; they may have breaks in flowering, and clones arise in clone-forming species.
Old generative individuals are plants characterized by a sharp decrease in reproductive function, the processes of death prevail over the processes of new formation, and disintegration increases.
Subsenile individuals are old vegetative plants, characterized by the cessation of fruiting, a decrease in power, an increase in destructive processes, a simplification of the life form, and the appearance of immature-type leaves.
Senile individuals are old plants, characterized by extreme decrepitude, reduction in size, and the secondary appearance of juvenile characteristics (shape of leaves, pattern of shoots).
Dying individuals are plants with an extreme degree of senile state, when only some tissues and dormant buds remain alive, unable to develop shoots.
The distribution of individuals in a cenopopulation across age groups is called the age spectrum. The counting unit can be genets, ramets or modules. The number of seeds is not taken into account. If the age spectrum includes only young individuals that have not reached the reproductive phase of development, then the population is called invasive. It is not capable of self-sustaining; it is a young population. If all or almost all age groups are represented in the age spectrum, then the population is called normal. It is capable of self-maintenance by generative or vegetative means. Depending on the predominance of a particular generative group, normal populations are divided into three types:
young normal - these are populations in the age spectrum of which young generative individuals predominate;
middle-aged normal - these are populations in the age spectrum of which middle-aged generative individuals predominate;
3) old normal - these are populations in the age spectrum of which old generative individuals predominate.
If all age groups are represented in the age spectrum, then the population is called normal complete, but if some age groups are missing, then it is called normal incomplete. If a population contains age groups, starting with old generative individuals, then such a population is called regressive. It is not capable of self-sustaining; it is an old population. An invasive population can turn into a normal one, and it can turn into a regressive one.
Depending on environmental conditions, one species may experience polyvariance in ontogenesis, which affects the structure of the age spectrum. As conditions improve, ontogenesis is shortened in some individuals, and lengthened in others. The age spectrum can vary depending not only on external conditions, but also on the resistance of the species themselves to these conditions. In some species, throughout their range and under a wide range of conditions, normal cenopopulations maintain a constant age spectrum. This age spectrum, which depends primarily on the biological properties of the species, is called basic. It is mainly found in edificatory species. They have a balanced number of emerging and dying individuals in each age group.
In the age composition of unitary organisms, three age groups can be distinguished, differing in relation to reproduction:
pre-reproductive individuals are young individuals who have not reached puberty and therefore are not yet capable of producing offspring;
reproductive individuals are sexually mature individuals that produce offspring;
post-reproductive individuals are old individuals who have lost their reproductive function and therefore no longer produce offspring.
The duration of existence of each age group in relation to life span varies greatly among different organisms. U modern man these three ages are approximately the same. Among primitive people
the post-reproductive period was much shorter. The prereproductive period in some organisms is very long compared to others. For example, in cicadas it lasts 17 years, the reproductive period lasts only one season, and the post-reproductive period is absent altogether. The absence of a post-reproductive period is observed in some insects (mayflies) and fish (salmonids).
The quantitative ratio of age groups in a population serves as an indicator of the trend in its size. Typically, a population with a large proportion of young individuals is rapidly growing; with a uniform age distribution, the population is in a stable state, and with a large proportion of old individuals, the population size decreases.
The age composition of unitary organisms is often reflected using a diagram, placing age groups one above the other symmetrically relative to the center, resulting in age pyramids, the nature of which can be used to predict future changes in population size. There are three main types of age pyramids (Fig. 3).
Age
Developing population
Rice. 3. Types of age pyramids in populations of unitary organisms (according to L. Tsvetkova et al., 1999)">
Individuals in a population
/> Fig. 3. Types of age pyramids in populations of unitary organisms (according to L. Tsvetkova et al., 1999)
If the age pyramid has a wide base, then such a population is called developing or growing and its number will increase in the future, which means it can be used. If the age pyramid is correct, then the population is called stable, and its numbers can remain at the same level for a long time; it can also be used, but in limited quantities. If the age pyramid has a narrow base, then such a population is called aging or dying out and it needs protection.
The long-term breeding part of the population is called the population stock, and that part of the young individuals that have reached sexual maturity is called the annual replenishment of the population. In species with one generation throughout the life cycle, the reserve is almost equal to zero and reproduction is carried out entirely by recruitment. In species with a large number generations, the supply is significant, and a small but stable share of replenishment.
When used by humans natural populations taking into account their age composition has important, because allows you to predict changes in numbers for the near future. Such forecasts are widely used in fisheries and fishing.
The age structure of the population is the distribution of people by age groups and contingents for the purpose of studying demographic and socio-economic processes.
This approach helps form well-informed assumptions regarding future trends in mortality, fertility, and other important processes happening on Earth. It even allows you to predict the demand for services and goods. What is the essence of this approach and what are its features? This is what we will talk about now.
Distribution principle
To begin with, it is important to stipulate that the concept of an age group is often identified with a term such as “generation”. It is not right. A group is just a collection of people united by the same age. But a generation includes citizens who were born in a certain period.
In the age structure of the population, the composition of the population is usually considered in ten-year, five-year, and one-year groups. Bottom line marked, which is logical, but the top one remains open. Usually they simply indicate “Over 75.”
Division by ability to work
In Russia this is what is most often used. The population is divided into age groups based on their ability to work. It looks like this in the following way:
- From 0 to 15 years. Citizens who are not of working age due to their youth.
- Men from 16 to 59 years old and women from 16 to 54 inclusive. People of working age.
- Men and women are over 60 and 55 years old, respectively. Retirement age exceeding working age.
This is a conditional gradation. It is used to determine the level of the economically active population. And here it is necessary to note an important nuance. And we are, of course, talking about raising the retirement age.
The need to increase this figure has been discussed for a long time. This is justified by the fact that many citizens simply do not have enough experience to receive decent payments.
The changes already took place a year ago, on January 1, 2017. Not much, but only for six months. Now men can retire at sixty and a half, and women at fifty-five and a half.
The age is planned to increase annually. If we believe the forecasts, then in 8-12 years in our country men will retire at 65. And women are 63 years old. And this change is difficult to characterize as positive. After all, now in order to receive payments a person must have at least 20 years of experience in a particular field. And before, before 2017, there were 15.
Also, experts do not believe that these reforms will help the country get out of economic crisis. The percentage of working people aged 45 to 65 will increase sharply, and young citizens, on the contrary, will no longer find employment in budgetary structures. They will try their luck either in other countries or organize their own business. And they will have nowhere to earn experience, since all the places will be busy people, which could go on a well-deserved rest.
And these conclusions, by the way, are made taking into account the notorious age structure population. That is why it was decided to increase the pension threshold gradually. A sharp jump will not lead to anything good.
Measurement and classifications
When talking about the sex and age structure of the population, it is necessary to make a reservation that certain classifications are used for its research. The oldest is considered to be Chinese, and it looks like this:
- Up to 20 years old. Period of youth.
- From 20 to 30. The age when people enter the tank.
- From 30 to 40. The period during which citizens actively perform public duties.
- From 40 to 50. The time when people recognize their own delusions.
- From 50 to 60. It is believed that this is the last creative period.
- From 60 to 70. Retirement is called the desired age.
- From 70 and above. Old age.
There is also Zumberg's classification, which is more condensed. There are only three stages: children (from 0 to 14), parents (from 15 to 49), and grandparents (from 50 and older).
It is important to note that the gender and age structure of the population differs in developed countries and in not particularly productive ones. In successful countries, the percentage of older people is much higher. But there are more children in developing countries.
Attitude total number The ratio of pensioners and very young members of society to working-age citizens is called the demographic load. It comes in two types. One is called “gray” (the ratio of the retired population to the working population), and the second is “green” (the ratio of children to workers).
Demographic changes
They are constantly observed in the age structure of the population. IN Lately The birth rate is decreasing, but the average life expectancy is increasing. This cannot be called a demographic crisis. The proportion of the population of older ages is simply increasing. This phenomenon gave it its name - demographic aging.
Of course, there were preconditions. This phenomenon was the result of long-term demographic changes. These include, mainly, shifts in the nature of mortality, fertility, population reproduction, and also migration.
You can refer to UN statistics. In 2000, the world population aged 60 years and above was approximately 600,000,000. And this figure is three times Furthermore, which was observed in 1950. Over time, by 2009, it had grown to 737,000,000 people. Moreover, experts, having studied in detail the factors of the age structure of the world's population, came to the conclusion that in 2050 the proportion of elderly people will exceed the 2 billion mark.
Which country is “leading” in this indicator? An age structure with a high proportion of elderly people is observed in Japan. At the time of 2009, the total number of residents of this country accounted for 29.7% of those over 60. The smallest figure is in the UAE and Qatar. There are only 1.9% elderly there.
Aging society
This global problem, which is the largest in economically. If you believe UN forecasts, then in a little more than 30 years, about a quarter of the planet’s population will be pensioners. And in developed countries, for every working person there will be one elderly person who is unemployed due to age.
Solving the problem of aging society requires an integrated approach, including social, economic and technological aspects. First of all, the calculation is made that the age of the so-called “active old age” will increase. We are talking about those cases when older people lead full, eventful lives, and at the same time look youthful. Fortunately, there are many of them.
Medicine is moving forward by leaps and bounds, so maintaining visual youth and good health is reality. And thanks to industrial automation, aging people with deteriorating conditions have the opportunity to continue working. Plus, it appeared distant work, which is convenient for the elderly. And many managed to master it.
But it is worth returning to the topic of changing the age structure of the population. To assess the aging process of society, a convenient scale is used, compiled by the demographer J. Beaujeu-Garnier. It was modified by E. Rosset, and this is what happened (see table below).
What are the forecasts for Russia? If already in 2000 the Russian Federation reached the last level of demographic old age (18.5%), then by 2050, according to expert calculations, it will grow to 37.2%.
Influencing factors
It is impossible not to mention them. Factors influencing the age structure of the population include:
- Life expectancy of people, the ratio of fertility and mortality.
- Biological features. U different nations The birth ratio of girls and boys is different.
- Losses during wars. The most terrible factor, which is the most serious.
- Migration. According to statistics, in countries that actively accept citizens of other states, there is a large number of men mature age.
- Economic state of the country.
The last factor is considered by many to be the key one. Not surprising, since it affects the availability of jobs and public health.
Sex and age structure
The ratio of women and men can hardly be called equal. There are fewer representatives of the strong part of humanity. This is all due to gender imbalance - a demographic effect that arises due to wars and domestic policy(one family - 1 child).
In the last century, the ratio was as follows: 52% women and 48% men. Now there are 1% fewer representatives of the strong part of humanity. It would seem that one percent is so little. Yes, but now there are about 7.6 billion people living on Earth. And if converted into a ratio, then this 1% will turn into 76,000,000 men.
Continuing the topic of the gender and age structure of the population, it is worth saying that such disproportions are an obstacle to creating families. Fortunately, the violations that occurred during the Great Patriotic War have already been smoothed out to a certain extent. Now disparities are observed due to differences in fertility and mortality. But they are not catastrophic. Census data will help you verify this:
- 1959 There are 1,249 women per 1,000 men.
- 1989 There are 1,138 women per 1,000 men.
- 1999 There are 1129 women per 1000 men.
It is interesting that in cities the number of men under the age of 25 more in number women who are in the same category. In rural areas the indicators are different. There, the male population is higher than the female population in all categories up to 50 years. It is believed that this is due to the migration of girls to big cities.
The situation in Asia using the example of China
This is also very interesting topic. The age structure of the population of Asian countries differs significantly from that in European countries. Especially China. After all, this is the state with the largest population in the world. The country has conducted a census six times, with the most recent one in 2010. At that time, there were 1,339,724,852 people living in China. And only the mainland part was taken into account. Taiwan (23.2 million), Macau (550 thousand) and Hong Kong (7.1 million) were not taken into account.
Over 10 years, China's population grew by ~94,600,000 people. And according to the official population counter, in 2016 the figure rose to 1,376,570,000.
Interestingly, for every 100 women in China there are 119 men. There are more representatives of the strong part of humanity in all age categories. The only exceptions are pensioners. The data is:
- From 0 to 15 years. For every 100 women there are 113 men.
- From 15 to 65 years. For every 100 women there are 106 men.
- From 65 and above. For every 100 women there are 91 men.
It is impossible not to mention the “one family - 1 child” policy adopted in the country with the aim of reducing the birth rate. To normalize the demographic situation, they began to popularize late marriages, complicate the process of creating a family, provide free abortions, etc.
Average ages
They are also interesting to consider. The statistics are quite recent, for 2015. The average age of the population is also called median. It divides all citizens living in the country into two groups - younger than the specified indicator and older. It is difficult to list all states, so the data is selective:
- Monaco - 51.7.
- Germany and Japan - 46.5.
- UK - 40.4.
- Belarus - 39.6.
- USA - 37.8.
- Cyprus - 36.1.
- Armenia - 34.2.
- Tunisia - 31.9.
- UAE - 30.3.
- Kazakhstan - 30.
- Maldives - 27.4.
- South Africa - 26.5.
- Jordan - 22.
- Congo - 19.8.
- Senegal - 18.5.
- South Sudan - 17.
- Niger - 15.2.
In Russia average age population is 39.1 years old. Compared to most European countries, where the indicators are above 40, we still have a young society.
Social structure of the population
It is also necessary to talk about it. This concept means the functioning in society of such elements and structures as the production team, family and social groups. This is important because all of the above is a source of population reproduction, livelihoods and protection of vital interests.
Social structure, according to the scheme that was proposed by the Soviet sociologist A.V. Dmitriev, consists of five groups:
- Elite. The upper class of society. Consists of the old party elite, which has merged with the new political elite.
- Working class. This group is also divided into layers according to various signs(industry, classification, etc.).
- Intelligentsia. This includes writers, teachers, doctors, military personnel, etc. In general, educated people with a respected specialty.
- "Bourgeoisie". Businessmen and entrepreneurs.
- Peasantry. They do housework.
The changes taking place in society allow us to make predictions for the future. Predict how society and the quality of life of the population will be functionally and spatially transformed (freedom, security, welfare, etc.).
About population reproduction
Finally, it is worth talking about the demographic crisis. Speaking in simple language, this is a reduction in population. Considering that the world's population is beginning of XXI century was 6 billion, and by 2011 it had crossed the line of seven billion, there is no need to talk about a demographic crisis. If the dynamics remain the same, then in 2024 the number of people on our planet will be 8 billion.
But if we talk about Russia, then population decline is still observed. From 1925 to 2000, the birth rate in our country decreased by 5.59 children. The most noticeable decline occurred in the 80s and 90s. It was during this period that the mortality rate exceeded the birth rate.
Now the situation has smoothed out somewhat. But the birth rate cannot be called active. Scientists identify the following reasons influencing this:
- Demoeconomic factors. People have neither demographic nor economic motivation.
- Social factors. People have no desire to have children or are unable to support them (a reference to a decline in living standards).
- Medical and social factors. The quality of life and health decreases. The state does not support public health, mortality is rising, there is widespread alcoholism and drug addiction. People don't want to have children in such conditions so that they don't have to live in them.
The age composition of the population is the distribution of the population by age groups, which are characterized by the number of selected groups and their relationship with each other. In demographic analysis, one-year-olds (with a difference of 1 year) and five-year-olds (1-4,5-9, .... 95- 100 years) age groups, and in a more generalized study - ten-year groups - with an interval of 10 years.
For special study purposes, specific age criteria are adopted. So, in Russian statistics Three large population groups are distinguished according to their role in the demographic situation:
Young population (children, pre-working age) - from 0 to 15 years.
Adult population (working age) - from 16 to 60 (women - up to 55) years
Elderly population (pensioners, post-working age) - after 60 (55) years
This grouping, as we see, also serves to determine the working age, and therefore is used to calculate the number of able-bodied and disabled categories of the population.
In UN statistics, the criteria for identifying three large population groups are somewhat different: childhood include persons under 14 years of age, the adult working population - people from 15 to 65 years of age, and those over 65 years of age - the elderly. This is due to the widespread practice abroad of attracting people to earlier labor activity and later retirement (in countries where pensions are established). Thus, age groupings developed in demography are also used in socio-economic policy to solve problems of labor activity, pensions, and education.
Taking into account the population structure and national traditions Each country also establishes other age criteria, such as the age of majority - the age of legal and social responsibility and labor law(in Russia - from 16 years old); age of conscription for military service (in Russia - from 18 years); age of marriage (in Russia - from 18 years old) and others.
For demographic studies, it is important to distinguish the age from 15 to 49 years, which is defined as reproductive - the age of “fertility” - the ability to bear children. The birth rate largely depends on the size and share of this population group.
Every society develops a fairly stable age structure of the population. Based on the predominance of rex or other ages, the population is characterized as “young”, “mature” or “aging”.
A graphic representation of population structures with a predominance of different age groups was proposed in 1930 by the German scientist F. Burgdörfer using pyramids of different configurations (Fig. 4). number
Rice. 4. Types of age structures (according to F, Burgdörfer): A - young (growing) population; B - mature (stationary) population; B -- aging (declining) population.
The young population is represented by a pyramid in the shape regular triangle, which reflects a large proportion of children (at the base of the pyramid) and a small proportion of elderly (at the top), which creates conditions for population growth.
The mature population - with a predominance of adult generations and a moderate proportion of other ages - is depicted by a bell-shaped figure, which shows stability, stability of the population, the possibility of replacing outgoing generations with younger ones. This composition of the population maintains its current size.
The aging population - with an increased proportion of older ages compared to child generations - is reflected by an urn-shaped figure, the base of which is visually narrower than its main bowl. This indicates a possible decline in the number of people, in which younger generations do not make up for the number of those leaving.
Thus, the composition of the population determines the main trends in changes in its size (with other equal conditions). In the modern world, the ratio of age groups of the population is as follows (Table 4).
Table 4
Age composition of the population of the modern world (2000)
|
Regions of the world |
Age groups - as a percentage of the population |
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|
over 65 years old |
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The world at large |
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The developed countries |
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Incl. Russia |
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Developing countries |
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These tables, presented for large groups of countries, smooth out the large differences between individual countries. However, it is clear from them that developing countries have the youngest populations, where the child population makes up more than a third of all residents, and the share of the elderly barely reaches 5%. In some African countries the share of children rises to 45-50% of the population, and the elderly make up 1-2%. This is due to both high birth rates and high mortality rates in early ages.
IN developed countries The composition of the population is older, both due to low birth rates and increased life expectancy of the entire population. Therefore, the share of children here is reduced to 1/5 of the population, and the share of old people reaches 10-15%. Composition Russian population typical for developed countries. ((SITELINK-S126)continued(/SITELINK))
The Russian population classification by age provides for the distribution of the population into the following groups:
from 1 day to 7 days – newborns;
from 7 days to 1 year – infants;
from 1 year to 3 years – early childhood;
from 4 years to 7 years – first childhood;
from 8 years to 12 years (boys) and
from 8 years to 11 years (girls) – second childhood;
from 13 years to 16 years (boys) and
from 12 years to 15 years (girls) - teenagers;
from 17 years to 21 years – boys;
from 16 to 20 years – girls;
from 22 to 35 years (men) and
from 21 to 35 years (women) – I period of maturity;
from 36 years to 60 years (men) and
from 36 years to 55 years (women) – II period of maturity;
from 61 to 74 years (men) and
from 56 years to 74 years (women) - older people;
from 75 to 90 years old people;
over 90 years old are long-livers.
3. Age group.
Age group – a group of people united by two characteristics: age and some socio-economic or other characteristic.
In Russia the following are distinguished: age groups :
1). Nursery (from 0 to 2 years).
2). Preschool (from 3 to 6 years).
3). School (from 7 to 15 years).
4). able-bodied (from 16 to 59 years old - men; from 16 to 54 years old - women).
5). Reproductive (childbearing) (women aged 15 to 49 years).
6). Conscript (men aged 18 to 49 years).
7). Electoral (men and women over 18 years of age).
In Russian statistics, as well as UN statistics special place occupy enlarged population groups , based on two criteria: age and ability to work. When distributing the population into one of three enlarged groups, the following assessment criteria are used:
1). Young disabled population:
From 0 to 15 years – for Russia;
From 0 to 14 years – for UN countries.
2). Adult working population:
From 16 to 60(55) years – for Russia;
From 15 to 65 years – for UN countries.
3). Elderly disabled population:
Over 60(55) years old - for Russia;
Over 65 years old - for UN countries.
As these data show, the period of working life in the UN countries is much wider than in Russia: the population is involved in work earlier and retires later.
3.3.4. Age accumulation
Annual groups are subject to deformation under the influence of age-related accumulation.
Age accumulation – denser concentration of population in certain areas age groups compared to neighboring groups.
Age accumulation is the result of distortions in information about the age composition of the population.
Reasons for distortion of information about the age composition of the population:
1. Use in statistical observations(censuses) method of survey in which there is no documentary verification of the correctness of the data.
2. The tendency of people to round numbers to "0" at the end (or "5", etc.).
3. Psychological factor: women do not want to be older, old people want to be younger, teenagers are in a hurry to be adults; therefore, when interviewed, these people may deliberately reduce (or increase) their age.
There are various methods for measuring age accumulation . All of them are based on the use of indices (coefficients) characterizing the strength of age-related accumulation. Most common Whipple index (coefficient) , measuring age accumulation at ages ending in "0" and "5":
Where 
- population aged 25, 30, ..., 60 years;
- population aged 23, 24, …, 62 years.
The lower the age accumulation, the lower the Whipple index will be.
Methods to reduce age-related accumulation:
1. Record the date of birth of the person being copied, not his age.
2. Methods for smoothing out protrusions and depressions in the age structure (artificial methods):
Graphic method;
Moving average method
and others.
All these methods make it possible to determine the age composition that is more consistent with reality.
In general, the manifestation of age accumulation depends on the level of development of the country. In developed countries its importance is reduced to a minimum.
The age and sex composition of the population represents the ratio of age and sex groups. Age group is a group of people of the same age. This is the main element of the age structure of the population. Depending on the purposes of the study, age groups are distinguished: one-year and enlarged: 5-year-old and 10-year-old. However, larger age groups are also used to assess general structural changes. Depending on the reproductive ability of people, a generation of children is distinguished - up to 15 years old, a generation of parents - 16-49 years old, a generation of grandparents - 50 years old and older. Classification according to the population's ability to work is more often used. It identifies population groups below working age (pre-working) age - 0-14 years, working age (working) - 15-59 years (in some countries 15-64-65 years) and older than working age (post-working) age - 60 or 65 years and older. With more detailed analysis B. Ts. Urlanis proposed the identification of the following age groups: pre-working - up to 15 years (including toddlers up to 2 years, preschool 3-6 years, and school age 7-15); working age - 16-59 years (including youth 16-24, maturity 25-44, late maturity 45-59 years); after work – 60 years and older (including elderly age-60-69, early old age 70-79, extreme old age 80 years and older).
Based on analysis age-related changes V various organs and tissues, as well as the body’s performance, a classification of age boundaries for the second half of a person’s life has been adopted. Age 45-59 is defined as average, 60-74 - elderly, over 75 years - senile, in which centenarians are distinguished - people aged 90 years and older.
To characterize the sex and age composition of the population, age-sex pyramids are used, which graphically represent the distribution of the population by sex and age. These are diagrams in which the number of people of each age (or their share in the population) is depicted by a horizontal bar of a certain scale. The bars are located one above the other in order of increasing age values, on the left side of the diagram for men, on the right for women. Age and sex pyramids They are usually built in one-year or 5-year age groups, and sometimes in 10-year groups. However, age-sex pyramids built by large age groups conceal the detailed features of the age and sex composition of the population.
The age and sex structure of the population is, first of all, the result of evolution. The type of population reproduction, formed by the processes of fertility and mortality in the present and past periods, determines the ratio of the population of different age groups. At the beginning of the 20th century. Swedish statistician and demographer G. Sunberg introduced into science the concept of three types of age structures of the population: progressive, stationary and regressive. The progressive type (1) is characterized by a high proportion of children and a low proportion of the older generation in the entire population. Its formation is based on an expanded type of reproduction. The age pyramid has the shape of a triangle, the base of which depends on the birth rate. In the stationary type (2), which is based on a simple type of reproduction, the age pyramid has the shape of a bell with an almost balanced proportion of children and old age groups. A narrowed type of reproduction leads to the formation of a regressive type, the age pyramid of which has the shape of an urn (3). It is characterized by a relatively high proportion of elderly and old people and a low proportion of children.
To characterize the age structure of the population, triangular diagrams are sometimes used by concentration zones, which simultaneously show the ratio in the population of three large age groups - 0-14 years, 15-19 years and 60 years and older. The field of such a diagram can show the age structure of several states or regions.
The formation of the age structure of the population is greatly influenced by wars, as a result of which, firstly, a decrease in the population of conscription age occurs, and secondly, a sharp decrease in the birth rate. At the regional, and sometimes at state level large changes in the age structure may result from the generally increasing number of men of working age.
As a result of these reasons, the edges of the age pyramid become uneven and reflect historical changes in the pattern of population growth and decline. Such violations leave marks on the age structure of the population for a long time. For example, on the age pyramid of Russia as of January 1, 1996, traces of a sharp decline in the birth rate during the First World War and civil war 1914-1922 (1), period of collectivization, forced industrialization 1928-1935. and 1932-33 (2), during the years of the Great Patriotic War and post-war devastation (4), as well as traces of the losses of men during the war of 1941-45. (3). The lower population size in the 14–33 age groups (5) is due to the “demographic echo” of declining fertility across generations. The smaller generation born during the Great Patriotic War, having reached reproductive age, gave birth to relatively fewer children than neighboring generations. The decrease in the child population aged 0-8 years (6) is caused not only by a decrease in fertility as a result of a decrease in the number of women of reproductive age born in the second half of the 60s and early 70s, but mainly by the impact of the socio-economic crisis.
Analysis of the age-sex pyramid allows us to characterize not only the demographic history of the state, but also to predict demographic situation in future. A decrease in the population aged 0-8 years will lead to a decrease in the birth rate in 2013-2020. and the formation of a new “failure” in the pyramid.
Age structure of the world population (%)
| Countries or territories | Proportion of population aged (years) | ||
|---|---|---|---|
| 0-14 | 15-64 | 65 and older | |
| World | 32 | 62 | 6 |
| 45 | 52 | 3 | |
| North Africa | 41 | 56 | 4 |
| West Africa | 46 | 51 | 3 |
| East Africa | 47 | 50 | 3 |
| 50 | 48 | 2 | |
| 30 | 64 | 6 | |
| Central Africa | 46 | 51 | 3 |
| South Africa | 38 | 58 | 4 |
| America | 29 | 63 | 8 |
| 22 | 65 | 13 | |
| Central America | 37 | 59 | 4 |
| 47 | 49 | 4 | |
| 33 | 62 | 5 | |
| Caribbean region | 31 | 62 | 7 |
| Asia | 33 | 62 | 5 |
| Western Asia | 39 | 57 | 4 |
| 52 | 45 | 3 | |
| Price and Yuzh. Asia | 38 | 58 | 4 |
| 37 | 59 | 4 | |
| East Asia | 26 | 67 | 7 |
| 16 | 70 | 14 | |
| 22 | 67 | 11 | |
| 19 | 67 | 14 | |
| Northern Europe | 20 | 65 | 15 |
| Western Europe | 18 | 67 | 15 |
| 18 | 66 | 16 | |
| Eastern Europe | 22 | 66 | 12 |
| Southern Europe | 18 | 68 | 14 |
| Albania | 33 | 62 | 5 |
| 16 | 68 | 16 | |
| 26 | 64 | 10 | |
| Australia | 22 | 67 | 11 |
| islands | 47 | 50 | 3 |
Rogachev S.V. Socio-economic differentiation of countries of the world. // . Geography © 2, 1997.
Sex and age pyramid (as of January 1, 1996) 
Territorial differences in reproduction predetermined a significant difference in the age structure of the world population. Countries with simple and narrowed types of population reproduction and with a high average are characterized by “aging of the nation.” They are characterized by a low proportion of children and a high specific gravity population of working age and older than working age. These include European countries, North America, Australia and , Georgia, China, Russia. Europe has the smallest proportion of children. In 34 countries in this part of the world, the share of children is less than a quarter, including in 22 countries - less than 1/5. And in only four countries, and this figure is more than 1/4, reaching a maximum of 33% in Albania. Europe is also the “oldest” region of the world. In 11 states, the proportion of the population over 65 years of age is 15% or more, and in 18%. Japan is characterized by the same proportions as in most European countries. The rest of the world has a more optimal age structure. They have a lower proportion of old people and a higher proportion of children.
Grouping of countries of the world according to the ratio of children and elderly population
| Share of children in the total population (%) | Proportion of old people in the total population (%) | |||||||
|---|---|---|---|---|---|---|---|---|
| Regions of the world | less than 20 | 20-30 | 30-40 | more than40 | up to 5 | 5-10 | 10-15 | more than15 |
| North Africa | — | — | 5 | 2 | 7 | — | — | — |
| West Africa | — | — | — | 16 | 15 | 1 | — | — |
| Eastern Africa | — | — | 3 | 13 | 13 | 3 | — | — |
| Central Africa | — | — | 1 | 7 | 7 | 1 | — | — |
| South Africa | — | — | 1 | 4 | 5 | — | — | — |
| Severn. America | — | 2 | — | — | — | — | 2 | — |
| Central America | — | — | 4 | 4 | 8 | — | — | — |
| South America | — | 2 | 10 | 1 | 10 | 2 | 1 | — |
| Caribbean region | — | 8 | 5 | 1 | 2 | 11 | 1 | — |
| Western Asia | — | 4 | 8 | 7 | 15 | 3 | 1 | — |
| Cent. and Yuzh. Asia | — | — | 5 | 9 | 13 | 1 | — | — |
| South-East. Asia | — | — | 7 | 2 | 8 | 1 | — | — |
| East Asia | 2 | 4 | 1 | — | 2 | 4 | 1 | — |
| Northern Europe | 5 | 5 | — | — | — | — | 7 | 3 |
| Western Europe | 8 | — | — | — | — | — | 7 | 1 |
| Eastern Europe | 2 | 7 | — | — | — | 2 | 7 | — |
| Southern Europe | 7 | 4 | 1 | — | 1 | 3 | 8 | — |
In the majority developing countries characterized by an expanded type of reproduction and low life expectancy, there is a high proportion of children and a very small proportion of the elderly population. The youngest continent is Africa. Here, in no state does the share of children fall below 30%, and in 42 it is more than 40%. Yemen has the highest share; this figure reaches 52%. Very, which was typical quite recently for the countries of these regions, and in some, and still persists, determines the low proportion of the population of older ages. In 20 American and 38 Asian countries, the share of these age groups is less than 5%. The lowest proportion of old people is ,. Populations in middle age groups have a great influence on the formation of their age structure.
The sex composition of a population is measured by the number of men per 100 or 1000 women, sometimes the proportion or percentage of males and females in the entire population or individual age groups. The following factors have a decisive influence on the formation of the gender structure of the population.
1. The numerical ratio of boys and girls among births. It is 105-106 boys per 100 girls or 51.2% boys. These indicators vary slightly across countries and over time, rarely being more than 107 and less than 104. This ratio is explained by human biology. The ratio of the numbers of male and female zygotes during fertilization is approximately 125-130 male embryos per 100 female. However, intrauterine mortality of male fetuses is significantly higher than that of female fetuses.
2. More high mortality rate among the male population, due to several reasons:
- biological characteristics of the body of a man and a woman. The female body is more resistant to external influences;
- employment of men in more traumatic and health-hazardous industries National economy;
- more common among the male population bad habits: alcoholism, drug addiction and substance abuse, smoking.
3. Wars, in which predominantly men die, have a huge impact on disproportions in the gender composition of the population. This is also reflected in the age and sex structure of the Russian population. In age groups over 70 years of age, there is a significant excess of the female population.
4. Population migration. The gender composition of the migrating population depends on the sectoral affiliation of secondary vocational and higher education educational institutions, structures of the national economy. In areas of developed heavy industry, new buildings predominate male population, in the regions - and the service sector - women's. The specialization of educational institutions in training personnel for “male” or “female” industries leads to gender imbalance in young age groups. Differences in population mobility also have some influence on the gender composition. As a rule, the male population is more mobile.
The highest proportion of the female population is typical for the countries of Eastern and southern Europe(Baltic countries, Slavic republics of the ex-USSR, Moldova,) and from 52 to 54%.
The maximum proportion of men is observed in countries, reaching the highest rates in Kuwait and Qatar, respectively, 61.4 and 66.2%. The very high proportion of men in the oil-exporting Gulf countries is due primarily to mass immigration work force, mostly men.
Demographic encyclopedic dictionary.-M.: Sov. encyclopedia 1985. p. 422.