Stages of Population Growth Class Notes

Stages of population growth—class notes

Stage ONE: a preindustrial society, death rates and birth rates are both high and fluctuate rapidly according to natural events, such as drought and disease, to produce a relatively constant and young population. No countries are still in this stage

Stage TWO: Developing country, the death rates drop rapidly due to improvements in food supply and sanitation, which increase life spans and reduce disease. These changes usually come about due to improvements in farming techniques, access to technology, basic healthcare, and education. Countries in this stage include Nigeria, Kenya and Bangladesh

As mortality declines in Stage Two, population grows rapidly (a "population explosion") as the gap between deaths and births grows wider. Note that this growth is not due to an increase in fertility (or birth rates) but to a decline in deaths.

The decline in the death rate is due initially to two factors:

1. improvements in the food supply brought about by higher yields in agricultural practices prevent death due to starvation.

2. significant improvements in public health reduce mortality, particularly in childhood. These are not so much medical breakthroughs (Europe passed through stage two before the advances of the mid-20th century) as they are improvements in water supply, sewerage, food handling, and general personal hygiene following from growing scientific knowledge of the causes of disease

Stage THREE birth rates fall due to access to contraception, increases in wages, urbanization, a reduction in subsistence agriculture, an increase in the status and education of women, and other social changes. Population growth begins to level off.

Stage Three moves the population towards stability through a decline in the birth rate. In general, the decline in birth rates in developed countries began towards the end of the 19th century in northern Europe and followed the decline in death rates by several decades. This was spurred by the Industrial Revolution and later industrialization. Many countries are currently in this stage including India, Mexico and Brazil.

Possible Reasons for decline in birth rate:

1. In rural areas continued decline in childhood death means that at some point parents realize they need not require so many children to be born to ensure a comfortable old age

2. Increasing urbanization changes the traditional values placed upon fertility and the value of children in rural society

3. Increasing female literacy and employment lower the uncritical acceptance of childbearing and motherhood as measures of the status of women.

4, Improvements in contraceptive technology

Stage FOUR: Birth and death rates decline. Birth rates may drop to well below replacement level as has happened in countries like Italy, Spain and Japan, leading to a shrinking population, a threat to many industries that rely on population growth. The large group born during stage two ages and creates an economic burden on the shrinking working population. Death rates may remain consistently low or increase slightly due to increases in lifestyle diseases due to low exercise levels and high obesity and an aging population in developed countries.

Now some believe STAGE FIVE exists: now widely accepted that a fifth stage is needed to represent countries who have undergone the economic transition from manufacturing based industries into service and information based industries, or what is called Deindustrialization. Countries such as Germany, Sweden, Italy, and most notably Japan, whose populations are now below their replacement levels. This means that there is a natural decrease in the population as birth rates have fallen below the death rate.