Concept of underpopulation is just the opposite of overpopulation. Underpopulation occurs when the population of an area is too small for full utilization of its resources.
The condition of under-population may also appear when the resources of an area can support a larger than the existing population without lowering the standard of living or without creating any type of unemployment.
Types of Underpopulation:
Under-population may be classified into two types: absolute under-population and relative under population.
Absolute under-population is not common but rare and may be found only incompletely isolated populations where the degree of replacement of people is extremely low. The absolute under-population is less obvious than relative under population.
On the contrary, the relative under-population is common in large countries due to insufficiency of resource development. For example parts of Australia, Brazil, Canada, Russia, Argentina, Congo Democratic Republic (Zaire), etc. are underpopulated due to low technical level and very sparse distribution of the population.
The condition of overpopulation may be caused by a high rate of mortality due to repeating epidemics, famines, wars, etc. Such under-population may be controlled and restricted by improving medical facilities and thus reducing the mortality rate including infant mortality.