Population and Demography it also includes Birthrate and Mortality rates

1. Population
and
Demography

2. Population
A population is a subset of individuals of
one species that occupies a particular
geographic area and, in sexually
reproducing species, interbreeds.
A population is a group of individuals of
the same species that live together in a
region.

3. Total Population:
The total population or size of a community,
defined geographically or administratively, is the
number of persons residing there. It includes
persons living in households or families and the
“institutional” population, e.g., persons in
dormitories, jails, military barracks, and other
“group quarters.” The total population is
assessed at regular intervals by the national
census.

4. World population - is the total number of humans
currently living in the World. As of today, the total
population of the world is around 8.05 billion
people. The first billion was reached around 1800
and in just 200 years we reached 7 billion.
According to Population Division of United Nations
Department of Economic and Social Affairs, these
are the main milestones:
•1 billion - 1804
•2 billion - 1927 (in 123 years)
•3 billion - 1960 (in 33 years)
•4 billion - 1974 (in 14 years)
•5 billion - 1987 (in 13 years)
•6 billion - October 12, 1999 (in 12 years)
•7 billion - October 31, 2011 (in 12 years)

5. Most Populous Countries
More than 70% of the world population live in 20 most
populous countries of the world. There are just 2 countries
in the world with a population more than 1 billion people:
China and India. About 36 % of the World population live
just in these two countries. Despite the fact that China is
currently the most populous country in the world, India's
population growths much faster. And in 2023 India is
expected to become the most populous country in the
world. The five most populous countries in 2022 are China,
India, followed by the European Union (which is not a
country), the United States, the island nation of Indonesia,
and Pakistan.

6. Most Populous Countries
Top 20 most populous countries (01-04-2023)
No. Country Population %
1 China 1,458,983,776 18.13%
2 India 1,425,919,068 17.72%
3
United States of
America (USA)
337,571,831 4.19%
4 Indonesia 282,677,730 3.51%
5 Pakistan 232,873,494 2.89%
6 Nigeria 220,339,564 2.74%
7 Brazil 217,660,022 2.70%

7. Most Populous Countries
No. Country Population %
8 Bangladesh 169,859,498 2.11%
9 Russian Federation 146,083,557 1.82%
10 Mexico 133,608,908 1.66%
11 Japan 126,218,233 1.57%
12 Ethiopia 122,391,181 1.52%
13 Philippines 114,112,628 1.42%
14 Egypt 108,167,246 1.34%

8. Most Populous Countries
No. Country Population %
15 Vietnam 100,204,498 1.25%
16
Democratic Republic
of the Congo
96,846,751 1.20%
17 Turkey 88,208,759 1.10%
18 Iran 86,675,360 1.08%
19 Germany 83,809,859 1.04%
20 Thailand 70,506,874 0.88%

9. Least Populous Countries
Among the smallest countries in the world in terms of
population are the island nations in the Caribbean and the
Southern Pacific Ocean (Oceania).
The five countries in the world with the smallest population
are:
• Vatican City, an enclave in the city of Rome in Italy,
• Tuvalu, an island country in the Polynesian part of the
Pacific Ocean,
• Nauru, a tiny island country in Micronesia in the
southwestern Pacific Ocean,
• Palau, a Micronesian group of islands in the western Pacific
Ocean, and
• San Marino, a small country that forms an enclave in Italy.

10. Demography
A population has several characteristics or
attributes which are function of the whole group
and not of the individual. Different populations can
be compared by measuring these attributes.
The study of the group characteristics of a
population, their changes over time and prediction
of future changes is known as demography.
Demography is a scientific study of the human
population primarily with respect to size, structure
and development.

11. Demographics of the World for 2022
As of 1 January 2023, the population of the world was estimated to
be 8,046,949,318. This is an increase of 1.24 % (98,830,797 people)
compared to population of 7,948,118,521 the year before. In 2022
the natural increase was positive, as the number of births exceeded
the number of deaths by 98,415,064.
Below are the key figures for the world population in 2022:
•160,747,971 live births
•62,332,907 deaths
•4,060,130,059 males as of 31 December 2022
•3,986,819,259 females as of 31 December 2022
•4,345,352,632 people live in urban areas (54 % of total world
population)
•3,701,596,686 people live in rural areas (46 % of total world
population)

12. Demographics of the World 2022

13. POPULATION CHARACTERISTICS
I. Population Density
The size of the population is represented by its fundamental property
called density. It is generally expressed as the number of individuals or
the population biomass per unit area or volume.
Two Types of Densities
1. Crude Density
- Crude density is the density per unit of total space. Generally,
populations do not occupy all the space as whole because all area
may not be habitable.
2. Specific (or Ecological) Density
- Specific density is the density per unit of habitable space. It includes
only that portion of total space that can actually be colonized by the
population.

14. POPULATION CHARACTERISTICS
Determining Population Size
Population size can be measured by several methods:
1. Abundance
- Absolute number of individuals in population.
2. Numerical Density
- Number of individuals per unit area or volume. It is expressed
when the size of individuals in the population is relatively uniform,
as in mammals, insects and birds.
3. Biomass Density
- Biomass density is expressed in terms of wet weight, dry weight,
volume, and carbon and nitrogen weight per unit area or volume.

15. POPULATION CHARACTERISTICS
Population density can be calculated by the following equation:
𝑫𝒑 =
𝑵
𝑨
In this equation, Dp is the density of population, N is the total
population as a number of people, and A is the land area covered
by that population.
A is usually expressed in terms of either square miles or square
kilometers, especially when looking at human population.
The same population density formula applies to both human and
non-human populations.

16. POPULATION CHARACTERISTICS
World population density
The world population density is 59.1 people per square
kilometer (153.1 per square miles) as of January 2023.
This number is calculated using 8,046,949,318 people
as the world population and 136,120,354 km2
(52,556,368 mi2) as Earth's total area. This is the sum
of land and water areas within international
boundaries and coastlines of all the countries in the
world.

17. POPULATION CHARACTERISTICS
II. Natality
Natality refers to the rate of reproduction or birth per unit time.
It is an expression of the production of new individuals in the
population by birth, hatching, germination or fission.
𝑩𝒊𝒓𝒕𝒉 𝑹𝒂𝒕𝒆 𝒐𝒓 𝑵𝒂𝒕𝒂𝒍𝒊𝒕𝒚 𝑩 =
𝑵𝒖𝒎𝒃𝒆𝒓 𝒐𝒇 𝑩𝒊𝒓𝒕𝒉𝒔 𝒑𝒆𝒓 𝒚𝒆𝒂𝒓
𝑵𝒖𝒎𝒃𝒆𝒓 𝒐𝒇 𝑷𝒐𝒑𝒖𝒍𝒂𝒕𝒊𝒐𝒏 𝒑𝒆𝒓 𝒚𝒆𝒂𝒓
𝒙 𝟏𝟎𝟎𝟎

18. POPULATION CHARACTERISTICS
II. Natality
The maximum number of births produced per individual under
ideal conditions of environment is called potential natality. It is
also called reproductive or biotic potential,
absolute natality or maximum natality.
Natality varies from organism to organism. It depends upon the
population density and environmental factors. It is a general rule
that if the population density is usually low, the birth rate is also
low. This is so because the chances of mating between males and
females are low. If population density is unusually high, the birth
rate may also be low due to poor nutrition or physiological or
psychological problems related to crowding.

19. POPULATION CHARACTERISTICS
II. Natality
The maximum or absolute natality is observed when the
species exists under ideal ecological and genetic conditions. The
actual number of births occurring under the existing
environmental conditions is much less as compared to absolute
natality. It is referred to as ecological natality or realized natality.
It is not constant for population and may vary with the size of
population as well as with the time.

20. POPULATION CHARACTERISTICS
II. Natality
Example:
If a population of 1,000 female grizzly bears
produced 200 young in a year, the birth rate, or
fecundity, would be
(200/1,000) x 1000 = 200

21. POPULATION CHARACTERISTICS
II. Natality
Factors affect a population's birth rate:
• Age at first reproduction is also an important factor in
determining birth rate. Large, long-lived animals typically do
not become sexually mature until they are several years of
age. A vole or meadow mouse might become sexually mature
and breed for the first time at 18 days. An Asian elephant on
the other hand will typically be 9-12 years old when it first
breeds.

22. POPULATION CHARACTERISTICS
II. Natality
Factors that affect a population's birth rate:
• The birth interval is also important in determining birth
rates. A vole might produce a litter of young every 30 days
during the breeding season, but a grizzly bear may only
reproduce every 3 or 4 years.
• The average number of young produced is of obvious
importance in a population's birth rate. Some animals such as
fish or amphibians produce 100's or 1000's of eggs (not all of
them hatch of course), while many wildlife only have one
young at a time.

23. POPULATION CHARACTERISTICS
III. Mortality
Mortality refers to the number of deaths for every 1,000 people
per year. The death rate is correlated with the conditions of
country, for example, with the levels of prosperity, health, or the
occurrence of war.
𝑫𝒆𝒂𝒕𝒉 𝑹𝒂𝒕𝒆 𝒐𝒓 𝑴𝒐𝒓𝒕𝒂𝒍𝒊𝒕𝒚 𝑫 =
𝑵𝒖𝒎𝒃𝒆𝒓 𝒐𝒇 𝑫𝒆𝒂𝒕𝒉𝒔 𝒑𝒆𝒓 𝒚𝒆𝒂𝒓
𝑵𝒖𝒎𝒃𝒆𝒓 𝒐𝒇 𝑷𝒐𝒑𝒖𝒍𝒂𝒕𝒊𝒐𝒏 𝒑𝒆𝒓 𝒚𝒆𝒂𝒓
𝒙 𝟏𝟎𝟎𝟎

24. POPULATION CHARACTERISTICS
Mortality can be expressed in the following two ways:
1. Minimum or Specific or Potential Mortality:
It represents the minimum of theoretical loss of individuals
under ideal or non-limiting condition. Thus, even under the best
conditions individuals of a population would die of old age
determined by their physiological longevity. So it is constant for
a population.

25. POPULATION CHARACTERISTICS
Mortality can be expressed in the following two ways:
2. Ecological or Realized Mortality:
It refers to the death of individuals of a population under
existing environmental conditions. Since it varies with
environmental conditions, it is never constant. Mortality is
affected by a number of factors, such as, density, competition,
disease, predation and environment. Death rates vary among
the species and are correlated with birth rates.

26. POPULATION CHARACTERISTICS
Mortality can be expressed in the following two ways:
2. Ecological or Realized Mortality:
When the rate of natality is equal to the rate of mortality the
population is stationary. A birth death ratio (Births/death x 100) is
called vital index. For a population, the survival of individuals is more
important than the death. The number of births in relation to the
carrying capacity of the habitat is a fundamental factor influencing the
mortality rate. Because the number of survivors is more important
than the number of dying individuals, mortality is better expressed as
survival or as life expectancy. The life expectancy refers to the average
number of years the members of a population have left to live.

27. POPULATION CHARACTERISTICS
IV. Population Growth
The growth is one of the dynamic features of species
population. Population growth is the increase in population per
census year. Population size increases in a characteristic way.
When the number of individuals of population is plotted on the
y-axis and the times on the x-axis, a curve is obtained that
indicates the trend in the growth of population size in a given
time. This curve is called population growth curve.

28. POPULATION CHARACTERISTICS
IV. Population Growth
There are two types of growth curves:
1. Sigmoid Curve (S-Curve)
When a few organisms are introduced in an area, the population increase is
very slow in the beginning (positive acceleration phase or lag phase), in the
middle phase, the population increase becomes very rapid (logarithmic phase)
and finally in the last phase population increase is slowed down (negative
acceleration phase) until an equilibrium is attained and which the population
size fluctuates according to variability of environment. The level beyond which
no major increase can occur is referred to as saturation level or carrying
capacity. In the last phase the new organisms are almost equal to the number of
dying individuals and thus there is no increase in population size. In this way,
one gets sigmoid or S-shaped growth curve.

29. POPULATION CHARACTERISTICS
IV. Population Growth
There are two types of growth curves:
2. J-Shaped Curve
The second type of growth curve is J-shaped. Here in the first phase
there is no increase in population size because it needs some time for
adjustment in the new environment. Soon after the population is
established in the new environment, it starts multiplying rapidly. This
increase in population is continued till large amount of food materials
exist in the habitat. After some time, due to increase in population size,
food supply in the habitat becomes limited which ultimately results in
decrease in population size. This will result in J-shaped growth curve
rather than S-shaped.

30. POPULATION CHARACTERISTICS
IV. Population Growth
There are two types of growth curves:

31. POPULATION CHARACTERISTICS
V. Age Distribution
Age distribution is another important characteristic of population
which influences natality and mortality. Mortality, usually varies
with age, as chances of death are more in early and later periods of
lifespan. Similarly, natality is restricted to certain age groups, as for
example, in middle age-groups in higher animals. According to
Bodenheimer (1958), the individuals of a population can be
divided into pre-reproductive, reproductive and post-reproductive
groups. The individuals of pre-reproductive group are young, those
of reproductive group are mature and those in post-reproductive
group are old.

32. POPULATION CHARACTERISTICS
V. Age Distribution
The distribution of ages may be constant or variable. It is directly
related to the growth rate of the population. Depending upon the
proportion of the three age-groups, populations can be said to be
growing, mature or stable, and diminishing. In other words, the
ratio of various age groups in a population determines the
reproductive status of the population. Rapidly increasing
population contains a large proportion of young individuals, a
stable population shows even distribution of individuals in
reproductive age-group and a declining population contains a large
proportion of old individuals.

33. POPULATION CHARACTERISTICS
Ranges for age distribution (percentages):

34. POPULATION CHARACTERISTICS
VI. Population Fluctuations
The size and density of natural population show a changing pattern
over a period of time. This is called population fluctuation.
There are three types of variations in the pattern of population
change:
1. Non-fluctuating:
- When the population remains static over the years, it is said to
be non-fluctuating.

35. POPULATION CHARACTERISTICS
VI. Population Fluctuations
2. Cyclic:
- The cyclic variations may be (a) seasonal, and (b) annual.
Sometimes seasonal changes occur in the population and there are
additions to the population at the time of maximum reproduction
and losses under adverse climatic conditions. Common examples of
seasonal variations are met in mosquitoes and houseflies which area
abundant in particular season and so also the weeds in the field
during the rainy season. When the population of a species shows
regular ups and downs over the years, it is called annual cyclic
variation. It appears in the form of a sigmoid curve with regular drops
in population after peaks.

36. POPULATION CHARACTERISTICS
VI. Population Fluctuations
3. Irruptive
When the change in population density does not occur at regular
intervals or in response to any obvious environmental factor, it is
said to be irruptive fluctuation. In this there is a sudden
exponential or logarithmic increase in population density in short
time followed by equally quick drop in population density due to
deaths, and final return to normal level or even below that level.

37. Population Ratios
Population ratios are used to describe the degree
of balance between two elements of the
population, e.g., Males vs. females, children
versus women of reproductive age. The ratio is
normalized to refer to a standard unit of people,
usually 100 persons.

38. Population Ratios
Sex ratio:
The sex ratio is the ratio of males to females in the population
(normalized to 100).
𝑺𝒆𝒙 𝑹𝒂𝒕𝒊𝒐 =
𝑵𝒐. 𝒐𝒇 𝑴𝒂𝒍𝒆𝒔
𝑵𝒐. 𝒐𝒇 𝑭𝒆𝒎𝒂𝒍𝒆𝒔
𝒙𝟏𝟎𝟎
We calculate two sex-ratios: At birth, and in the total population.
The sex ratio at birth is fairly standard, around 105. Due to higher
mortality among males, the sex ratio in the total population switches
to 95-97. For populations with high levels of sex-selective
outmigration (such as male soldiers leaving a country for war),
particularly in certain age groups (e.g. aged 15-29), the sex ratio may
be even smaller.

39. Population Ratios
Sex ratio:
Ranges for sex ratios:
• Sex ratio at birth: 105 except for African
populations, where it is 102-103
• Sex ratio for total population: 101.5
• Sex ratio for population 15-49, with heavy male
outmigration: 99.9

40. Population Ratios
Dependency ratio:
This ratio quantifies the number of persons in a population
who are not economically active for every 100 economically
active persons in that population. It can be calculated by
dividing the population 0-14 years and 65 years and older by
the population that is in the 15-64 year age group.
𝑻𝒐𝒕𝒂𝒍 𝑫𝒆𝒑𝒆𝒏𝒅𝒆𝒏𝒄𝒚 𝑹𝒂𝒕𝒊𝒐 =
𝑷𝒐𝒑𝒖𝒍𝒂𝒕𝒊𝒐𝒏 𝒐𝒇 𝟎 − 𝟏𝟒 𝒚𝒓𝒔 𝒐𝒍𝒅 + 𝑷𝒐𝒑𝒖𝒍𝒂𝒕𝒊𝒐𝒏 𝒐𝒇 𝟔𝟓 𝒚𝒓𝒔 & 𝒂𝒃𝒐𝒗𝒆
𝑷𝒐𝒑𝒖𝒍𝒂𝒕𝒊𝒐𝒏 𝒐𝒇 𝟏𝟓 − 𝟔𝟒 𝒚𝒓𝒔 𝒐𝒍𝒅
𝒙𝟏𝟎𝟎
𝒀𝒐𝒖𝒏𝒈 𝑫𝒆𝒑𝒆𝒏𝒅𝒆𝒏𝒄𝒚 𝑹𝒂𝒕𝒊𝒐 =
𝑷𝒐𝒑𝒖𝒍𝒂𝒕𝒊𝒐𝒏 𝒐𝒇 𝟎 − 𝟏𝟒 𝒚𝒓𝒔 𝒐𝒍𝒅
𝑷𝒐𝒑𝒖𝒍𝒂𝒕𝒊𝒐𝒏 𝒐𝒇 𝟏𝟓 − 𝟔𝟒 𝒚𝒓𝒔 𝒐𝒍𝒅
𝒙𝟏𝟎𝟎
𝑶𝒍𝒅 𝑫𝒆𝒑𝒆𝒏𝒅𝒆𝒏𝒄𝒚 𝑹𝒂𝒕𝒊𝒐 =
𝑷𝒐𝒑𝒖𝒍𝒂𝒕𝒊𝒐𝒏 𝒐𝒇 𝟔𝟓 𝒚𝒓𝒔 𝒂𝒃𝒐𝒗𝒆
𝑷𝒐𝒑𝒖𝒍𝒂𝒕𝒊𝒐𝒏 𝒐𝒇 𝟏𝟓 − 𝟔𝟒 𝒚𝒓𝒔 𝒐𝒍𝒅
𝒙𝟏𝟎𝟎

41. Population Ratios
Dependency ratio:
Ranges for child/young dependency ratios:
• Least Developed: 80.8
• Developing: 53.1
• More Developed: 29.4

42. Population Ratios
Dependency ratio:
Example: A community has 41,650 children under age 14
and 6,800 persons age 65 and over. The total population
is 85,000.
The dependency ratio is:
(48450/(85000- 48450)) * 100 = 133.
You can also use the percentages from age distributions.
Example: (57%/43%) * 100 = 133.

43. Population Ratios
Child-woman ratio:
This ratio, the CWR, the ratio of children under 5 per 1000 women
of reproductive age. It is usually calculated by dividing the number
of children in the age group 0-4 (of both sexes) by the number of
women of reproductive age (15-49 years), and then multiplying by
1000.
𝑪𝒉𝒊𝒍𝒅 − 𝑾𝒐𝒎𝒂𝒏 𝑹𝒂𝒕𝒊𝒐 (𝑪𝑾𝑹) =
𝑷𝒐𝒑𝒖𝒍𝒂𝒕𝒊𝒐𝒏 𝒐𝒇 𝟎 − 𝟒 𝒚𝒓𝒔 𝒐𝒍𝒅
𝑷𝒐𝒑𝒖𝒍𝒂𝒕𝒊𝒐𝒏 𝒐𝒇 𝟏𝟓 − 𝟒𝟗 𝒚𝒓𝒔 𝒐𝒍𝒅 𝑾𝒐𝒎𝒆𝒏
𝒙𝟏𝟎𝟎𝟎
Ranges for the CWR:
• Least Developed: 710
• Developing: 400
• More Developed: 255

44. Population Ratios
Maternal mortality ratio:
The maternal mortality ratio(MMR) is the number of maternal
deaths per 100,000 live births. The numerator only includes
deaths to women during their pregnancy or in the first 6 weeks
after delivery.
This ratio is often used in lieu of the maternal mortality rate (the
number of maternal deaths per 100,000 women aged 15-49 per
year) because of the difficulty in obtaining accurate data to
calculate the rate of this relatively infrequent event in a
population which is subject to great underestimation, since all
pregnancies, births and deaths tend to be underreported .

45. Population Ratios
𝑴𝒂𝒕𝒆𝒓𝒏𝒂𝒍 𝑴𝒐𝒓𝒕𝒂𝒍𝒊𝒕𝒚 𝑹𝒂𝒕𝒊𝒐 (𝑴𝑴𝑹) =
𝑵𝒐. 𝒐𝒇 𝑴𝒂𝒕𝒆𝒓𝒏𝒂𝒍 𝑫𝒆𝒂𝒕𝒉𝒔
𝑵𝒐. 𝒐𝒇 𝑳𝒊𝒗𝒆 𝑩𝒊𝒓𝒕𝒉𝒔
𝒙𝟏𝟎𝟎𝟎
Maternal mortality ratio:
Ranges for the MMR:
• Least Developed: 1000
• Developing: 440
• More Developed: 12

46. Population Rates
Crude rates: A crude rate is used to describe the
frequency of a demographic event across the total
population, without regard to age or sex. The standard
reference period is one year. Because the population is
usually not the same at the beginning and end of the
year, the denominator for crude rates is the average of
the population at the beginning and end of the one year
period. The numerator is the number of vital events (e.g.,
births, deaths) observed for the total population in the
specified calendar year.

47. Population Rates
Crude rates:
Crude Birth Rate (CBR):
# of births per 1,000 persons in a population over a given period of
time (i.e. 1 year). This rate is most often used when looking at fertility,
though the crude measure does not account for important variations
in population fertility such as sex ratios, age distributions,
postponement or acceleration of marriage age, all of which can alter
the way that the crude rate should be interpreted.
Ranges of CBR:
• Least Developed: 40.4
• Developing: 23.1
• More Developed: 11.2

48. Population Rates
Crude rates:
Crude Birth Rate (CBR):
Example:
In the town of Kolikouro, Mali, there were 5663 births. The total
population was 149,442. The CBR is:
(5663/149,442 )* 1000 = 37.9

49. Population Rates
Crude rates:
Crude Death Rate (CDR):
# of deaths per 1,000 persons in a population over a given period
of time (i.e. 1 year). CDR is calculated in the same way as for CBR,
but with deaths instead of births as the numerator.
Ranges of CDR:
• Least Developed: 14.9
• Developing: 7.8
• More Developed: 10.2

50. Population Rates
Crude rates:
Crude Death Rate (CDR):
Example:
In the town of Ilocos Sur, there were 8118 deaths. The total
population was 685,743. The CDR is:
(8118/685,743 )* 1000 = 11.84

51. Population Rates
Rate of Natural Increase (RNI)
Is the speed at which a population is increasing in a
given period as a result of the interaction of the natural
demographic processes of birth and deaths. RNI is
actually the population increase per 1000 persons in a
population.
𝑹𝒂𝒕𝒆 𝒐𝒇 𝑵𝒂𝒕𝒖𝒓𝒂𝒍 𝑰𝒏𝒄𝒓𝒆𝒂𝒔𝒆 𝑹𝑵𝑰 = 𝑪𝑩𝑹 − 𝑪𝑫𝑹
Where,
CBR = Crude Birth Rate
CDR = Crude Death Rate

52. Population Rates
Look at this natural population change example for the UK in 2012.
Birth rate = 12.3 births per 1000
Death rate = 8.9 deaths per 1000
Rate of Natural Increase (RNI) = 12.3 – 8.9 = 3.4
However, this figure is per 1000 of the
population. We want it to be a percentage.

53. Population Rates
This is a positive number,
which means there is a natural
population increase.

54. Population Rates
Crude r (rate of growth of a population)
– Among locales where an estimate of the total
population is available each year, estimating the growth
of a population requires little more than dividing the
change in population at the end of the year by the
population at the beginning of the year. However, for
most settings, vital statistics are collected during
censuses only every few years. For these cases, we can
estimate the average yearly population growth using the
following formula, and solving for r.

55. Population Rates
Crude r (rate of growth of a population)
𝐏𝐭 = 𝐏𝟎𝐞𝐫𝐭
where:
Pt is the population # at the last year for which there is data
P0 is the population # at the first year for which there is data
e is the natural logarithmic constant
r is the unknown annual rate of growth
t is the number of years between Pt and P0
Ranges of r:
• Least Developed: 2.50%
• Developing: 1.48%
• More Developed: 0.30%

56. Population Rates
Crude r (rate of growth of a population)
Example:
In 1950, the population in thousands for the Dominican Republic
was 2,353. In 2000 (50 years later), it was 8,353. The rate of growth
is estimated as follows:
𝐏𝐭 = 𝐏𝟎𝐞𝐫𝐭
𝟖𝟑𝟓𝟑 = 𝟐𝟑𝟓𝟑𝐞𝐫(𝟓𝟎)
𝟖𝟑𝟓𝟑
𝟐𝟑𝟓𝟑
= 𝐞𝐫(𝟓𝟎)
Take logs and re-arrange, to:
(ln 8353 – ln 2353 ) = 50r ln e
(ln 8353 – ln 2353 ) /50= r
r = 2.54

57. Population Rates
Doubling Time
Is the amount of time it takes for a given quantity to double in size
or value at a constant growth rate.
We can find the doubling time for population undergoing
exponential growth by using the Rule of 70. To do this, we divide
70 by the growth rate (r)
𝑫𝒐𝒖𝒃𝒍𝒊𝒏𝒈 𝑻𝒊𝒎𝒆 =
𝟕𝟎
𝒓
Where,
r = population growth rate

58. Population Rates
Crude Net Migration Rate
– This rate illustrates the change in the population as it is affected
by people moving in and out of a country or other specified locale.
To calculate this rate, one would need to know both the number of
people that immigrated to (moved into) a country or the
designated district/subnational area and the number of people
that emigrated from (moved out of) a country or the designated
district/subnational area.

59. Population Rates
Crude Net Migration Rate
Then the crude net migration rate can be calculated using the following formula:
Crude net migration rate = (I – E )/ P * 1,000
where:
I is the number of immigrants or in-migrants
E is the number of emigrants or out-migrants
P is the total midyear population of the country or designated area.

60. Population Rates
Crude net migration rate
Example:
In 2002, a central African nation had 8,320 immigrants
and 7249 emigrants, according to their international
arrivals and departure statistics. The total population
(June 2002) was estimated as 1,258,000.
The NMR is
(8,320-7249)/1258000 * 1000 = 0.85

61. Population Rates
Crude net migration rate
Accurate and complete data on immigrants and emigrants is very
difficult to obtain. Immigrants may be incompletely observed because
countries may keep track of airplane arrivals, but seldom of all
arrivals. For this reason, it is generally preferred to calculate two
separate crude migration rates: Crude In-migration rate (I/P * 1000)
and Crude Out-Migration rate (E/P * 1000).

62. Population Aging
Population aging is an increasing median age in a population
because of declining fertility rates and rising life expectancy.
An aging population is one where the proportion of older
people is increasing. This is also known as ‘demographic
aging’.
Most countries have rising life expectancy and an aging
population, trends that emerged first in developed countries
but are now seen in virtually all developing countries. That is
the case for every country in the world except the 18
countries designated as "demographic outliers" by the United
Nations.

63. Population Aging
Asia and Africa are the two regions with a significant
number of countries facing population ageing. Within 20
years, many countries in those regions will face a
situation of the largest population cohort being those
over 65 and the average age approaching 50. In 2100,
according to research led by the University of
Washington, 2.4 billion people will be over the age of 65,
compared with 1.7 billion under the age of 20.

64. Population Aging
The size and proportion of the global population as relates to age over time
Source: http://study-aids.co.uk/dissertation-blog/population-ageing/

65. Which countries have ageing populations?
The proportion of the world population aged 65 and over increased
from 5% in 1950 to 7% in 2000 and 13% in 2017. While this is the
global average, Europe’s proportion increased to 15% in 2000 and
25% by 2017. Sweden were already at 10% in 1950, while Italy
achieved 22% by 2015.
Countries with the most people over 65 years old
• Japan – 26.3 %
• Italy – 22.4 %
• Greece – 21.4 %
• Germany – 21.2 %
• Portugal – 20.8 %
• Finland – 20.5 %
• Bulgaria – 20.0 %
• Sweden – 19.9 %
• Latvia – 19.4 %

66. How do we get an ageing population?
Population ageing is a result of people living longer and
having fewer children.
Declining mortality (those related to infectious diseases) and rising life expectancy
Source: http://valueofinnovation.org/power-of-innovation/

67. Why do populations age?
Factors that can impact population age distribution include:
• Life expectancy increases due to improved lifestyle (diet, exercise, not-
smoking) and importantly, access to quality health care — drugs,
treatments, expertise, surgical procedures, technology.
• Birth rate decline itself is driven by a number of factors:
 Improved availability, education and effectiveness of contraceptive
measures
 The rising costs of living influencing people’s decisions whether to
have children and how many
 Increasing number of women working
 Changing social attitudes (for example acceptance of alternative
lifestyles, including choosing not to have children)
 The rise of individualism
• Lack of inward migration (fewer younger people and families moving
to a given country, thereby reducing the average age).

68. Thank You!