Growth of Population

Population of a country should grow reasonably to match with growth in its gross domestic product to maintain the existing standard of living. Reducing growth or negative growth in population may be desirable if the standard of living should increase by more favourable per capita distribution of wealth.

But, negative growth of a population is not desirable because in the long run work force gets reduced and national productivity may come down. Normally, it is desirable to have modest increase in population to match with the growth of GDP of a nation. In such situations, the growth of national wealth matches with growth in population so that population will not put any pressure on the economy of nation. Many countries face problem of zero growth in population - which is also undesirable.

More dangerous feature is high growth rate of population. Higher growth rate generally leads to reduced per capita income, reduced standard of living, extreme pressure on all resources by excessive population - all leading to increased poverty rate.

The reasons for negative, positive and zero growth in population can be found out in death rate and birth rate.

i) Countries with negative growth in population - where death rate is higher than birth rate indicating higher percentage of older people than younger people or where emigration is larger than immigration.

ii) Countries with zero growth - where birth rate and death rates are equal and immigration / emigration are other also or negligible.

iii) Countries with modest growth - where birth rate is slightly higher than death rates or immigration is larger than emigrations.

iv) Countries with high growth - where birth rate is too high and death rate is too less or immigration is too much.

Characters of Population Growth

The growth of population follows either a sigmoid curve (S - curve) or an exponential pattern (J - curve).

Sigmoid curve

A sigmoid curve is characterised by a lag phase (wherever the growth rate is negligible), positive acceleration phase (wherever the growth rate is moderate), logarithmic phase (where in the growth rate is high) and negative acceleration phase (where in the growth rate is 0).

Over a larger time scale of say 2000 - 3000 years, when a country's population is studied such sigmoid pattern of growth can be visualised. The logarithmic phase of growth increase the population at faster rate. But the population - sooner or later - stabilizes itself attaining zero growth. The natural resources are limited to support a certain level of population. Beyond this level of increase of population, the growth is zero or negative.