It is defined as the number of persons per square kilometer of land. The population density of a country can be expressed mathematically as:
I. Population density = Total population
II. Total population = population density X land area
III. Land area = Total population
Population density may either be high or low depending on the number of people in a specified area of country. Generally, high population density occurs where there are many people in an area which leads to over population. Similarly, a low population density refers to a situation where there are few people in a specific area of land.
Ageing or Declining Population
This is an increasing percentage of Old people, while the relative percentage of children and workers are decreasing. Ageing or declining population is also known as stationary or static population. Factors responsible for an ageing population are as follow:
1. Decrease in birth rate: A fall or decrease in birth rate generally leads to declining population. This might be due to implementation of birth control and late marriages.
2. Increase in death rate: A rise or increase in the death rate of the young ones through epidermic or poor medical facilities generally leads to a reduction in the number of people in the country.
3. Emigration: The movement of young men or youth out of a country can also lead to declining population.
4. War: The existence of war also lead to declining population as able-bodied youth are lost during war.
5. Diseases: The outbreak of disease can also lead to decrease in population as this reduces the number of young ones within the country.
6. Natural disasters: Natural disasters like flood, earthquakes, etc, can lead to declining population, especially when the young ones are mostly affected.
7. Poor medical facilities: poor medical facilities generally lead to a decrease in population and when the young ones are the victims, ageing population is bound to set in.
Advantages of Declining or Decreasing Population
1. Reduction in government expenditure: A declining population have fewer people to cater for and as a result there will be a reduction in expenditure by government.
2. High standard of living: Standard of living has something to do with the number of people coupled with increasing resources, this will cause an icnrease in per capita income, which will result in higher standard of living.
3. Reduction in congestion: As a result of decrease in the number of people, there will be a corresponding decrease in congestion in terms of human, accommondation and vehicular traffic.
4. Creation of job: As a result of increase in the number of old people, there will be creation of more employment opportunities for the few labor force.
5. Increase in savings: With decreasing population there is an increase in savings on the part of government.
6. Increase in investment: As a result of the increase in savings, there will be enough capital for investment in important sectors of the economy.
Implications or disadvantages of declining or decreasing population
Reduction in labor force as a result of the decrease in the number of working class citizens or increase int he number of old people, there will be a reduction in the number of the labor force. Also a fall in gross domestic product (GDP) can occur-the fall in size of labor force would result in a fall in the productive capacity of the country. The small labor force, combined with its inability to make optimum use of available resources, results in low savings and a fall in gross domestic product.
Less mobility of labor as a result of the increasing number of old people, mobility of labor becomes difficult as old people may either stay at home or refuse to accept new ways of doing things. There is also risk of invasion due to the increase in the number of old people in a country, the risk if invasion by external forces is very high. Also one of its implications is that it leads to under-population and high dependency ratio. When the population of the old people and the children are higher than that of the working class population, ti will result in a high dependency ratio.
As a result of the increase in the number of old people, who are not taxable, the tax expected from the few that are working will be reduced and there will be a shift in demand in favor of goods and services used by the old people. There will be a fall in demand as a result of decrease in total demand for goods and services. Consequently, the amount of rewards associated with the factors of production will fall. For the developed nations, underpopulation is not a good idea at all. Though it may not be recommended to developing nations as well, because this will also kill the little production they generate and hence a fall in the nation’s economy.