Demographic Changes

The global population has been increasing rapidly since the 19th century, in large part because the mortality rate has fallen significantly as a result of the following factors:

• better hygiene

• better food

• advancements in medicine

• fewer epidemics

Since the early 20th century, life expectancy has also been increasing. According to United Nations (UN) data, the world’s population has grown from 1 billion in 1804 to 7 billion in 2011. This is a huge population increase.

Below are few key concepts to better understand demographic changes:

• fertility

• birth rate

• mortality

• life expectancy

• migration

• natural growth

• total growth

The fertility rate indicates the average number of births per woman in a country for a given period. The graph below shows how this rate changed in Canada from 1960 to 2017.

In Canada, this rate fell from 3.81 births per woman in 1960 to 1.50 children in 2017. Better access to birth control and abortion as well as the growing presence of women in the workforce explain this significant drop in fertility.

The birth rate is the number of births in a country in a given year. It is calculated based on the average number of births per 1000 inhabitants. The graph below shows how this rate changed in Canada between 1960 and 2017.

In Canada, this rate fell from 26.70 births per 1000 inhabitants in 1960 to 10.3 births per 1000 residents in 2017. Like the fertility rate, the reasons for this significant decline include better access to birth control and abortion and the growing presence of women in the workforce.

The mortality rate is the number of deaths per 1000 residents. The graph below shows how the mortality rate in Canada changed from 1960 to 2017.

The mortality rate varied considerably between 1960 and 2017 in Canada. The highest recorded mortality rate was 7.8 deaths per 1000 inhabitants between 1960 and 1963, while the lowest was 6.9 deaths per 1000 inhabitants in 1992. In recent years, this rate has increased from 7.10 deaths per 1000 inhabitants in 2012 to 7.50 deaths per 1000 inhabitants in 2017.

Life expectancy measures the number of years a person living in a certain country can expect to live. It varies greatly depending on the country’s health and social conditions. The graph below shows the evolution of life expectancy in Canada from 1960 to 2017.

In Canada, life expectancy has increased from 71.13 years in 1960 to 82.47 years in 2017. One of the main reasons for this increase in life expectancy is medical advancements. Over the same period, life expectancy in Haiti, a developing country, increased from 42.11 years in 1960 to 63.58 years in 2017. This is a similar increase to Canada, despite the lower life expectancy.

Migration is the movement of people from one place to another. Net migration is the number of immigrants (people entering a country) minus the number of emigrants (people leaving a country).

Number of immigrants - Number of emigrants = Net migration

The migration balance is often expressed as net migration, but calculated over a five-year period. In 1962, net migration to Canada was 178 066 people. In 2017, it was 1 100 000 people. The graph below shows how net migration changed in Canada from 1962 to 2017.

Natural growth is the difference between the number of births and the number of deaths over a given period. This growth is positive if the number of births exceeds the number of deaths (mortalities).

Number of births - Number of deaths = Natural growth

This growth is negative if the number of deaths exceeds the number of births. This occurs when the fertility rate is below 2.1 children per woman. It takes 2.1 children per woman to keep the population constant. This is called replacement level fertility.

Countries with fertility rates below the replacement level of 2.1 children per woman often rely on immigration to offset their negative natural growth

Migratory growth and net migration are the same thing. This is the number of immigrants (people entering a country) minus the number of emigrants (people leaving a country) in a given country in a given year. For example, if Chile has 1000 immigrants and 500 emigrants in 2020, the migratory growth would be 500. If there are more emigrants than immigrants, the growth is negative.

The total growth is the combination of natural growth and net migration, or in other words  migratory growth. Factors that lead to total population growth are births and immigrants, and factors that cause the population to decrease are deaths and emigrants. 

(birth - death) + (immigration - emigration)
Natural growth     Migratory growth  = Total growth   

Population growth is generally due to the adoption of pro-birth policies, such as financial support for families, and measures that promote immigration. To have positive total growth, governments must promote births and immigration. Better health care also plays a significant role in population growth.

• declining mortality rate

• declining fertility rate

• more births than deaths

• population growth

• higher life expectancy

• rising international migration

Below are a few explanations. Life expectancy is increasing due to decreasing poverty and advances in medicine and hygiene, as well as better access to essential resources such as clean water and food. In addition, international migration occurs in both developed and developing countries.

• declining birth rate

• declining fertility rate

• aging population

• adoption of policies to encourage births

• immigration to make up for the falling birth rate