Population Change

Fertility (Birthrate)

Fertility refers to the ability to conceive and produce. It is measured by counting the number of people (live births in a population). Fertility rate is influenced by factors like:

• Level of education
• Urbanization
• Birth control measures

Mortality (Death rate)

It refers to the number of deaths within a given population. Death rate can be categorized into:

1. Infant mortality rate. The number of deaths from 0–2 years.
2. Child mortality rate. Number of death of children aged between 1–5 years per 1000 live births.
3. Adult mortality rate. Number of adults dying per 1000 of the total population.

Migration

Migration is the movement of people from one place or region to another, which results in changes of residence, which may be temporary or permanent.

There are two types of migration, namely:

1. Internal migration.
2. External (International) migration.

Internal Migration

Internal migration is the movement of people within a country. It can be permanent, temporary, voluntary, or forced/involuntary.

Factors Influencing Internal Migration

1. Trade
2. Education
3. Search for jobs
4. Search for fertile soils

Forms of Internal Migration

1. Rural to Urban Migration. Refers to the movement of people from rural to urban areas or towns to search for jobs, better social services, and education.
2. Rural to Rural Migration. Refers to the movement of people from rural to rural, e.g., nomadic pastoralists.
3. Urban to Rural Migration. From towns to villages for investing, job purposes, setting up industries, and other projects.
4. Urban to Urban Migration. From one town to another for business, better employment, education, etc.

External Migration

External migration is the movement of people from their own countries to other countries.

Causes of Migration

1. Pressure on land. People move to areas with available land for cultivation, settlement, etc.
2. Availability of employment opportunities. Move to areas where employment is possible, e.g., rural to rural, to work in plantations, mines, etc.
3. Creation of wealth. People migrate to other countries with the aim of making wealth quickly, e.g., Tanzanians move to South Africa.
4. Religious conflicts. Which may result in chaos in a country.
5. Political instability. Like civil wars cause people to migrate, e.g., like that of Rwanda and Burundi has resulted in an influx of refugees in East African countries.
6. Natural disasters. Epidemic diseases, floods, earthquakes, drought may cause people to migrate to better areas where it is safe.
7. Forced migration. People forced to move from the area, e.g., Asians were expelled in Uganda during the leadership of military regime of Iddi Amin.
8. Cultural beliefs. People may move from one place to another due to cultural beliefs that are not friendly.

Population changes affect both the individuals as well as the nations at large. The effect can be positive or negative.

Effects on the Individual

A high fertility rate results in a large number of children that a family has to look after. Migration has its own effects on individuals in a number of ways:

1. Some individuals may change their lifestyles by becoming more sophisticated. This happens after gaining more skills and exposure to more sophisticated lifestyles where the individual migrated.
2. Some individuals after migrating to urban areas and getting jobs may take a much longer time to get married.
3. When spouses are separated for long periods, this may lead to break up of marriages. Either spouse may engage in extra-marital relationships during the period of absence of the partner.
4. Some individuals who migrate to urban areas lose their cultural values and this leads to immorality. Some turn to crime.
5. Some people save a lot of money from the income they get from working.

Effects on the Nation

1. Overpopulation is a situation whereby a region or country has such a high population that it cannot be supported fully due to a strain on the available resources.
2. Overpopulation also leads to unemployment or even underdevelopment of a nation or even under-employment.
3. Overpopulation leads to poor housing and health facilities because demand for these facilities is far greater than the supply.
4. Agricultural resources are underutilized because of shortage of land and traditional land tenure systems which hinder modernization of agriculture.
5. Slow industrial growth because of shortage of skilled labor. Although there is a large labor force, it is largely unskilled.

Overpopulation is a situation where people in a particular country are too many in relation to the available resources. This situation will force people to compete for the available resources and due to shortage of resources, there will be a general decline in the standard of living.

Overpopulation has both negative and positive effects.

Positive Effects of Overpopulation

1. Defense. A large population makes it possible to mobilize enough people to defend the integrity of the country in times of war or during any other emergencies.
2. Increase in labor market. Increasing population ensures increase in the labor force.
3. Large market. Investors would like to invest in a country with a large population. As the population continues to grow, so will be the growth in demand for food, shelter, clothing, etc.

Negative Effects of Overpopulation

1. Poverty. Because of overpopulation, the available resources would not be able to support the population, and this will result in abject poverty in the country.
2. Unemployment. A fast growth in population means a large number of persons coming to the labor market for whom it may not be possible to provide employment.
3. Social problems. Overpopulation brings about social problems such as bribery, prostitution, armed robbery, etc.
4. A decrease in the standard of living. Because of increased number of people, demand for essential commodities becomes highly competitive and it is those that are rich that would be able to afford them, thereby bringing a fall in the standard of living.
5. Poor housing and healthcare. Overpopulation leads to poor housing and inadequate health facilities because demand for these facilities is far greater than the supply.
6. Shortage of food. A large population increases the demand for food. This demand reduces the production of cash crops while increasing production of food crops.
7. Increase in government expenses. The government will always strive to provide all the necessary social services to the whole population. Thus, overpopulation would lead to increased government expenses on education, healthcare, housing, water supply, and all other social services.
8. Adverse effect on environment. Due to overpopulation, a large number of people are being pushed in ecologically sensitive areas such as hillsides and tropical forests.
9. Declining trend of agricultural development. Agricultural resources are underutilized because of shortage of land and traditional land tenure systems which hinder modernization of agriculture.

Underpopulation is a situation whereby the size of the population is small in relation to available resources of the country.

Causes of Underpopulation

1. An increase in death rate. Natural catastrophes such as earthquakes, flood, etc., will lead to an increase in death rate. Therefore, the country witnesses a reduction in human population.
2. A fall in birth rate. When a country decides to reduce the number of children for fear of eventual overpopulation or any socio-political factor, which does not favor children, the country becomes underpopulated.
3. A high level of emigration. A persistent increase in emigration over immigration leads to a reduction in a country's population.

Underpopulation also has positive and negative effects to a nation.

Positive Effects of Underpopulation

1. No congestion. A country with less population experiences little or no congestion because of low population density.
2. Abundant employment opportunities. Because of small size of the population, there will be enough job opportunities for the people.
3. Increased social and infrastructural facilities. An underpopulated country experiences a higher per capita in terms of social and infrastructural facilities available to the people in the country.
4. Availability of idle resources. The fact that a country is less populated means that the resources available in that country are higher than the number of people; hence, many idle resources would abound everywhere.

Negative Effects of Underpopulation

1. Lower standard of living. Underpopulation leads to lower standard of living because of inadequate labor force that would have conveniently boost output and production of goods and services.
2. Lack of adequate labor. Underpopulation results in shortage of labor with that effect of low investments and income. Inadequate labor leads to slow industrial growth.
3. Underutilization of resources. Resources are highly underutilized in a country with low population.
4. Inadequate market. A small population means a narrow market for the locally produced goods and services.
5. High transportation costs. When the population is small and scattered over a wide area, vehicles have to travel long distances to reach individuals. This makes transportation of goods and services expensive, a fact which hampers internal trade.
6. Lack of people to defend the country. At times of war and emergency, a country might find it difficult to mobilize enough people to defend it.
7. Low creativity. Underpopulation causes lack of pressure on the available resources. This hinders creativity because of limited competition.