In this lesson, you will learn what zero population growth means and how countries can achieve it. You will also learn which countries are currently at zero population growth and why.
What Is Population Growth?
As you may or may not know, the population of the world is currently increasing at an exponential rate. In other words, there are more and more people on this planet every year. Population growth can be defined as the change in the amount of people in a location during a certain period of time.
A positive population growth means that the number of people are increasing, while a negative population growth means that the number of people are decreasing.
What Is Zero Population Growth?
Zero population growth (ZPG) occurs when there is no change in the amount of people in a given time. Let’s say that Regular City, between Plainville and Example Counties, had ZPG last year. Does this mean that no one died or was born last year? You might think so, but it’s not that simple. When we talk about no change in the amount of people, we mean no net change.
No net change means that the number of people born equals the number of people who have died. Thus, zero population growth occurs when birth and death rates are equal. Birth rate refers to the amount of births per 1,000 people per year, while death rate refers to the amount of deaths per 1,000 people per year.
So in order for Regular City to have ZPG, Regular City has a birth rate of 33 and a death rate of 33 as well.When dealing with population growth, we must also take into account people moving in and out of an area. When dealing with Regular City, we assumed there was no emigration or immigration. In other words, we assumed no one left Regular City and no one entered Regular City.
In the real world, that’s not usually the case. In reality, zero population growth occurs when births and immigration equal deaths and emigration in a certain time period.
How Zero Population Growth Works
Looking at the ever-expanding population of the world, you may wonder how a country can achieve zero population growth.
Countries with low fertility rates tend to have lower population growth rates. Total fertility rate (TFR) refers to the average amount of children a woman has over her lifetime. The closer a country’s TFR is to 2.1, called the replacement rate, the more likely that country is to have ZPG. This means that a country where the women have roughly two children on average will more likely have ZPG.Typically, more developed countries tend to have lower population growth rates. Developed, or first world, describes countries that are industrialized and have higher standards of living, such as the United States, Canada, Australia, France, and Germany.
Developed countries are more likely to have lower growth rates due to the availability of birth control, family planning, and medical care, which means less babies will be born and these babies are more likely to live to adulthood.
What Are Population Pyramids?
Population pyramids are graphs that show the age and sex breakdown in a certain location. Above is an example of an age pyramid for Sudan in 2009. In this example, there are a high number of younger individuals and a lower number of older individuals. Because of this, Sudan has a rapidly expanding pyramid because the population growth is increasing.
Pyramids that are not quite as big on the bottom are just called expanding.Countries with ZPG have stationary population pyramids that are straighter on the sides and look less like a pyramid, which reflects the fact that birth and death rates are close to being even. An example of a stationary pyramid can be seen in Stage 3 of the image below. Countries with a decreasing population growth have contracting population pyramids, which come in at the bottom and can be seen in Stage 4 of the image below. This reflects the fact that the birth rate is lower than the death rate.
Countries with Zero Population Growth
According to the Population Reference Bureau, Austria and Russia had zero population growth rates in 2014. The following countries had growth rates within one tenth of zero: Slovenia, Spain, Italy, Greece, Bosnia-Herzegovina, Slovakia, Belarus, Monaco, Estonia, Finland, Denmark, and Taiwan.
Zero Population Growth (ZPG) occurs when the number of people who die and emigrate out of a country equals the number of people who are born or immigrate into a country. This means that there is no net change, which means that the number of people born equals the number of people who have died.
Birth rate represents the amount of births per year per every 1000 people, while death rate represents the amounts of deaths per 1000 people every year. Total fertility rate (TFR), which refers to the average amount of children a woman has over her lifetime, is helpful in determining whether a country has reached ZPG. The closer a country’s TFR is to 2.
1, the more likely it is to have ZPG. This is more common in countries that are industrialized and have higher standards of living, or developed countries. The population pyramid, or graph that shows the age and sex breakdown in a certain location, for a country with ZPG is called stationary because the amount of people in each age group is fairly equal. To give some real-world examples, Austria and Russia both had zero population growth in 2014.