Concept of over under and Optimum population

1. Change in birth rate — When the birth rate increases, population size also increases and when the birth rate decreases, population size also decreases.
2. Change in death rate — When the death rate increases, population will also decrease and vice versa.
3. Change in immigration — When the number of people entering the country increases, population will increase but when the number of people entering the country decreases, population will decrease.
4. Change in emigration — When the number of people leaving the country increases, population will decrease but when the number of people leaving the country decreases, population will increase.

Birth rate refers to the number of live births per thousand people.

$CBR = \frac{\text{Number of live births}}{\text{Total population}} \times 1000$

Example

Total population of T.Z — 36 million people

Number of live births — 1.2 million people

$BR = \frac{1.2}{36} \times 1000$

$= \frac{1200000}{36000000} \times 1000 = 33.3$

Therefore, for every 1000 people, 33.3 of them are new live births.

1. Cultural factor: In many low developed countries, a big number of children is looked at as a source of wealth, prestige, and increase during old age. In some cultures, it is again a sign of strength.
2. Early marriage: In many low developed countries, there are many instances of early marriages, where girls and boys marry as early as 13 years, which creates a high possibility of giving birth.
3. Polygamous tendency: Many men have a tendency of marrying more than one wife, which also contributes towards high birth rate.
4. Gender preference: In many low developed countries, couples have a tendency of targeting a certain gender, and in the process, they tend to have many kids.
5. Poverty: Children are looked at as a source of income through bride price. Early school dropouts due to lack of school fees, families cannot afford family planning facilities such as pills.
6. Ignorance: Many people in low developed countries are ignorant about the danger of high birth rate and also different precautions to be taken against unwanted pregnancies.
7. Idleness and lack of recreation facilities also contributes towards high birth rates since the couples are together most of the time.

1. Family Planning: The government has introduced family planning programs that are offered by many health centers all over the country at a very less fee.
2. Mass education: The government is also trying its level best to educate the masses about the danger of high population and high birth rate through political gatherings, workshops, seminars, etc. under the concerned ministries.
3. The education policy: More schools have been constructed. School fees have been subsidized. Sex education has been introduced.
4. The government also tries its level best to develop social and economic infrastructures in rural areas in order to reduce idleness among people in rural areas.
5. The government has also used the law in order to reduce the birth rate as below:

The government set up sentences on rape and school pregnancies, and it has also discouraged early marriage.

This refers to the number of deaths per thousand people per annum.

$DR = \frac{\text{Number of deaths}}{\text{Population size}} \times 1000$

Example

Total population = 30 million

Number of deaths = 3 million

Calculate the death rate.

$DR = \frac{3}{30} \times 1000$

$DR = \frac{1}{10} \times 1000$

$= 100$

Therefore, for every 1000 people, 100 die.

1. Poor or insufficient devices in number of ways.
2. Lack of enough food supplies, which has created a high level of famine, and many have died.
3. Political Instability: Many LDCs are experiencing political instabilities through wars, tribal conflicts, religious conflicts, which have resulted in many killings.
4. Disease: In many LDCs, there are a lot of chronic diseases such as AIDS, TB, and Malaria, etc., which have claimed many lives.
5. Lack of enough medical staff.
6. Lack of enough health centres.
7. Lack of enough hospital facilities.
8. Poverty: Poor nutrition, inability to buy medicine.
9. Poor sanitation and lack of clean water.
10. Witchcraft.

Population density refers to the number of people per square km.

Example

Total population = 4 million

Area in sq km = 200,000

Calculate population density.

$PD = \frac{4000000}{200000}$

$PD = 20$

Negative effects

1. High rate of crimes.
2. Easy spread of diseases.
3. Low standard of living because of lack of enough goods and services.
4. Unemployment due to high supply of labour.
5. More pressure on social services such as schools, hospitals, etc.
6. High rent due to shortage of houses.
7. Sanitation problems.
8. More pressure on natural resources, which results in environmental degradation.

Positive effects

1. High market, which will stimulate economic activities.
2. More labour supply.
3. Production will tend to be more competitive.
4. High government concern in areas with high population density.

This refers to the components of a certain population in a number of areas such as age, sex, occupation, education, etc.

1. Age Structure: This is the distribution of population according to age, and here population is divided into the children, adults, and the old. The children and the old are regarded as the dependents (economically inactive), whereas the adults are regarded as economically active. This refers to the ratio between the dependents and the working-age population.

   $\text{Dependency Ratio} = \frac{\text{Number of dependents}}{\text{Number of working-age population}}$

   Given:

   Age group	Number of people
   0 – 16	5,766,259
   17 – 59	3,667,882
   60<	984,501

   a) Calculate the dependency ratio

   $\text{DR} = \frac{\text{Number of dependents}}{\text{Number of working-age population}}$

   $\text{DR} = \frac{5766259 + 984501}{3667882}$

   $\text{DR} = \frac{6750760}{3667882}$

   $\text{DR} = 1.835$

   $\text{DR} = 1.8$

   $\text{DR} = 1:1.8$

   Every 1 person in the working age is responsible for approx. 2 dependents.

1. High level of crimes rate.
2. It can result in an increase in street children.
3. It can result in an increase in government expenditure.
4. It results in a low labour force.
5. It results in low savings and investment.

Factors that affect life expectancy include:

1. Poor nutrition
2. Poor sanitation
3. High occurrence of diseases such as Malaria
4. Poor health services
5. Poverty
6. Low level of education

This refers to the distribution of population on gender basis, i.e., males and females. From this, we can know how many males and females compare in the population of a certain country.

Sex Ratio

$\text{Sex Ratio} = \frac{\text{Males}}{\text{Females}}$

Assuming females are 6 and males are 2, calculate sex ratio:

$= \frac{2}{6}$

$= \frac{1}{3}$

$\text{Sex Ratio} = 1:3$

For every 1 male, there are 3 females.

1. Education Structure — This shows the distribution of population according to the level of education, i.e., the educated, the uneducated, and the various levels of education. It is on the basis of this that we can determine the illiteracy rate and literacy rate.
2. Occupation Structure — This is the distribution of population according to different occupations. This helps to know the number of people employed in different professions, sectors, etc. It also helps to know the number of employed and the unemployed.
3. Income Structure — This shows the distribution of population according to different levels of income, and it is from this that we can know the number of those who are low-income earners, medium, and high-income earners.

This is a situation when there are more and more old people as compared to the adults and the children.

This is the common feature for more developed countries due to high life expectancy.

1. It increases the burden to the government and society, as such people become dependent; therefore, the government and society have to spend more in providing services to such people.
2. Decline in the labour force, which affects population.
3. Decline in efficiency of work as old people are always less energetic, both mentally and physically.
4. Increase in demand for goods demanded by the old, e.g., walking sticks, spectacles, etc., but decrease in demand for goods for children.
5. Limited change in the society as the old tend to be more conservative.
6. Limited mobility of labour as many old people are not willing to move from one geographical area to another.

This refers to how population is distributed in relation to the available resources.

There are three types of spatial population distribution:

1. Overpopulation
2. Underpopulation
3. Optimum population

This is the situation when the number of people living in a certain geographical area is greater than the resources available. Therefore, under such a situation, the labour force available is more than the resources available.

Indicators of Overpopulation

1. Low standard of living
2. Food shortage
3. Housing shortage
4. High level of unemployment
5. High pressure on natural resources, which tends to result in environmental degradation.
6. Congestion on social and economic infrastructure, e.g., roads, schools, etc.

This is when the population of a certain country balances with the amount of resources that are available; therefore, the country's labour force size can fully utilize the available resources.

Indicators of Optimum Population

1. There is full employment.
2. There is maximum standard of living.
3. There is adequate provision of social services.
4. There is maximum utilization of resources.
5. There is maximum output.

Note: It is difficult to know that a country is at optimum population at a particular point because:

1. The stock of resources cannot be accurately known.
2. The population size may as well not be accurately known.
3. Time also affects the size of population and the stock of resources, whereby they tend to change as time goes on.

This is the situation when the number of people in a certain geographical area is less as compared to the resources available; therefore, the available labour force is inadequate to maximally utilize the available resources.

Indicators of underpopulation

1. Small market size.
2. Low standard of living.
3. Shortage of labour force.
4. Underutilization and idle resources.

Positive effects

1. Big labour force, which can be used in exploiting resources.
2. Big market for goods and services.
3. Big source of revenue to the government through taxes.
4. High output produced in the economy and hence a high national income level.
5. It will also result in more competition in a society, which will result in more creativity and inattentiveness.

Negative effects

1. High level of unemployment due to excessive labour supply.
2. High dependency ratio.
3. Housing shortage.
4. High rate of crimes.
5. High government expenditure in provision of social and economic infrastructures.
6. More pressure on social services such as hospitals, schools, etc.
7. High pressure on natural resources, which will result in environmental degradation.
8. Excessive demand for goods and services, which will result in demand-pull inflation.

It is the average number of years a person can live in a given country at a specific period of time.

The life expectancy in LDCs such as Tanzania is low as compared to MDCs due to the following factors:

1. Poor nutrition
2. Poor sanitation
3. High occurrence of diseases such as Malaria
4. Poor health services
5. Poverty
6. Low level of education

This refers to how people are spread in a certain geographical area; therefore, this can be even or uneven.

1. Social and economic infrastructures: Population density is high in areas where there is availability of social services like hospitals, education, and economic services like roads, electricity, tap water, and telecommunication, while in areas where there are poor social services and economic infrastructure, the population density is very low.
2. Climate: Population density is high in areas where climate is favorable for the cultivation of different crops. Examples of such areas in Tanzania are Kilimanjaro, Mbeya, and Victoria Basin, while in areas where climate is unfavorable for the cultivation of different crops, the population density is low, e.g., in areas of the central parts of Tanzania.
3. Soil fertility: Fertile soil attracts human settlements for agricultural activities, while infertile soil will discourage human settlement due to its inability to produce enough harvest; hence, in areas with fertile land, the population density is high.
4. Political factor: Many people prefer to settle in areas with political stability and peace than in areas where there is political instability.
5. Employment opportunities: In areas where employment opportunities are easily available due to presence of many economic activities such as manufacturing, the population density is high, while areas with limited economic activities and employment opportunities, the population density is very low.
6. Natural hazards: Such as volcanic eruptions, floods, droughts, etc. Those areas with such problems, population density usually tends to be low and vice versa.
7. Cultural factors: Some of the tribes tend to live in areas that were left by their ancestors as their heritage and continue to produce on those areas so as to create clans, and hence high population density.

It is the complete process of collecting, comparing, and publishing demographic and social economic data regarding people living in a certain country at a certain period of time.

It is a systematic process of collecting, analysing, and publishing of the population data of people living in a certain geographic area at a specific period of time.

In Tanzania, the population census exercise is done after every ten (10) years.

After such a period of time, fundamental changes are expected to take place regarding the population structure and the socio-economic factors.

1. It is important to the government in the planning process in allocating funds on the provision of social basic services such as education, health, etc.
2. It helps to know the population distribution of people in a certain area, and it is on the basis of this that it can be known as to which places are under or overpopulated.
3. It helps to know the birth and death rate in the country, which helps to establish the population growth rate.
4. It helps to determine the dependency ratio in the country by knowing the number of the young and old.
5. It is also important for political reasons, e.g., in determining comparisons over time as regards population size, the birth rate, death rate, etc., between countries.
6. Population census data is also important for international comparisons over time as regards population size, the birth rate, death rate, etc., between countries.
7. Population census is also important in knowing the population of the country. E.g., according to the 2002 population census, it was known that Tanzania has a population size of around 36 million people.

1. Lack of enough funds: Many LDCs, Tanzania inclusive, lack enough funds to carry out a smooth population census exercise. It is upon this that some countries at times postpone and others carry out in an undesirable manner.
2. Transport and communication, especially in rural areas, which results in failure to access some of the areas, delay in reporting data, and high transport cost.
3. Unreliable data on issues such as level of income, education level, age, and so on, due to the fact that some people at times are not willing to give the right information regarding those data.
4. Lack of enough skilled manpower, which normally results in employing unqualified people for the exercise, which normally results in mistakes and errors.
5. Lack of enough cooperation from the public for the exercise. E.g., some refuse to be interviewed, others don't even allow access to their homes, and others give wrong information.
6. Communication problems. There are some areas where people don't know Swahili.
7. At times, the government manipulates the population census data for its own political reasons. As a result of this, population data does not reflect what is actually on the ground.