Explain some of the ways that fertility, mortality, and migration influence population size.

Explain some of the ways that fertility, mortality, and migration influence population size.

Fertility, mortality, and migrations are primary factors contributing to population changes. Fertility refers to the number of children a woman can bear in her reproduction years. Secondly, the birth rate is typically used to measure fertility and it is considered as the number of live births for every 1000 people in a population annually. Therefore, there are significant differences between birth rates worldwide, if it is high, it will contribute to population growth and vice versa.  Secondly, mortality refers to the number of deaths occurring in a population. It is expressed as the number of deaths per 1000 people annually.  If these cases increase due to factors such as epidemics and war, then it can reduce numbers among the affected population.  More so, migrations occur when people move from one place to another, and they affect population. For instance, if people are displaced from one place to another because of wars, the number of people in the affected areas will reduce.

What does Thomas Malthus say about population growth?

Thomas Malthus had a fascinating argument on population growth.  He argued that there is an exponential growth in human population, but food production was growing slowly. Therefore, it will be catastrophic if the number of people increases at the expense of food supply. For instance, many people will die due to food shortages, but this will bring the population back to a sustainable level.  His argument implies there are positive and preventive checks that can help to keep population growth in check.  For example, if human population continues to increase, it is likely to lead to consequences such as resource depletion, poverty, and inter-community wars.  In this case, death rates will be higher than birth rates, and population growth will reduce considerably.

 

What is the demographic transition theory?

 

A demographic transition theory depicts the relationship between birth and death rates in reference to economic development.  In this theory, a country passes through different stages of population growth as the economy develops. For instance, in the first phase, there is high population growth due to high birth rates while in phase two, economic activities increase, but they do not affect birth rates.  The mortality rates also decline because of improvements in food production and healthcare services. However, in stage three, population grows at a diminishing rate due to the effects of economic development on birth rates.  The fourth phase, both birth rates and death rates are almost the same, they are low, and they population growth is almost stationary.

What is the demographic divide?

Demographic dividend explains how economic growth can result from changes in a country’s age structure. It happens when people shift from living short lives and having large families to living longer lives with small families. Furthermore, if fertility and mortality rates decline, the will significantly change the age structures.