Types of population pyramid
The types of population pyramid are the different graphs that can be drawn in a demographic pyramid, taking into account the population structure of the territory in relation to the variables sex and age.
Thus, we must know, first of all, that a population pyramid is a graphic representation that shows the characteristics of a population belonging to a locality, city or country, at a moment in time.
The pyramid has a vertical axis, which shows the different age ranges of a population. Age ranges that are five years are generally used (for example, 0 to 4 years, 5 to 9 years, 10 to 14 years, and so on). Likewise, the pyramid has a horizontal axis, which measures the volume of people who fall into each of the selected ranges. This volume is shown with horizontal bars. The length of each bar has a direct and proportional relationship to the number of individuals in the population. That is, the length depends on the number of individuals that are integrated in that age range.
Therefore, once we know what a population pyramid is, we must know that, depending on the structure that a territory presents, the graph will draw one type of pyramid or another. Thus, in population structures with many young people, we can see a traditional pyramid, while, in territories with a more abundant adult population, we could see an inverted pyramid.
Due to this, there are types of pyramid, established by experts, which, depending on the pyramid drawn, offer us characteristics about the population in question.
With that said, let's look at the types of population pyramid!
Types of population pyramid
Among the types of existing population pyramid, we could highlight the 4 main types: progressive population pyramid, stationary or stagnant pyramid, regressive pyramid and unbalanced pyramid.
Progressive population pyramid
The progressive population pyramid is the population pyramid that characterizes underdeveloped and developing economies. The population tends to have many children, so a large percentage of the population is usually concentrated in the lower part of the distribution. In turn, due to the lower life expectancy, as we advance in the age ranges, they present a lower population density.
The drawing, therefore, shows us a wide base and a thinner top.
Progressive population pyramid example
The population of Guinea, for example, is characterized by presenting this type of pyramid, as we can see below:Source: PopulationPyramid.net
Regressive population pyramid
The regressive population pyramid is just the opposite of the progressive population pyramid, as indicated by the figure it draws and the name itself.
Thus, we are talking about the type of pyramid that characterizes rich countries, which have, and as we well know, a very low birth rate in contrast to that of developing and underdeveloped countries. In the same way, as it has a very high life expectancy, the high area of the distribution, where the oldest population is concentrated, has a high population density.
Therefore, the drawing that we see in this type of pyramids is the opposite of the previous one. The bases are usually thin and the upper parts, or what we call the tops, are usually thick, since they have a small young population, and a large adult and aging population.
We also know this type of pyramid as an inverted pyramid.
Example of a regressive population pyramid
The population of Spain, for example, is characterized by presenting this type of pyramid, as we can see below:
Stagnant or stationary population pyramid
The stationary population pyramid, or stagnant population pyramid, is the one that characterizes developing countries. For this reason, there is a balance in the distribution, a consequence of the fact that mortality has begun to be controlled, but the birth rate is still quite high.
This type of population pyramid presents a birth rate and a mortality rate that, in general, do not undergo significant variations over a long period of time. Some experts consider this pyramid as the intermediate step between a progressive pyramid and a regressive pyramid.
Therefore, the drawing that we see in this type of pyramids is that of a similar base and structure throughout the entire pyramid, progressively reducing from a certain age range.
Example of a stationary or stagnant population pyramid
The population of Chile, for example, is characterized by presenting this type of pyramid, as we can see below:Source: PopulationPyramid.net
Unbalanced or unbalanced population pyramid
It is the type of pyramid that characterizes countries in which an event has occurred that has altered the demographic structure, generating significant disproportions such as those that we will see below.
Thus, we are talking about a type of pyramid that we can see in countries that have participated in a war, and have suffered the loss of a large part of the male population. Also in countries that have suffered waves of migration, where children and women have had to leave the country en masse due to a specific event. In general, countries that have been affected by some notable event, leaving the population disproportionate.
Therefore, the drawing that is observed in this type of pyramids does not follow any pattern. It is characterized by being irregular and presenting random shapes, which do not correspond to the other side of the pyramid, and so on the other way around.
Example of an unbalanced or unbalanced population pyramid
The population of Qatar, for example, is characterized by presenting this type of pyramid, as we can see below:Source: PopulationPyramid.net