How does the population change?

There are three major reasons that the population of a place can change. They are births, deaths, and migration. Let us look at each one and how it can cause the population to change.

Births: Every time a baby is born, this causes the population to increase by one. If many babies are born in a country, we can expect the population of that country to grow. 

^{The birth of babies helps the population grow.}

Deaths: Every time someone dies, this causes the population to decrease by one. If many people die in a country, it can slow down the growth of the population. If a very large number of people die in a short period of time, it can cause the population of the country to decrease. 

^{Deaths slow down the rate at which the population grows.}

Migration: Migration is the movement of people from one place to another. Migration can cause the population of places to change.

Migration can happen inside of a country. Sometimes people leave one part of a country and go to live in another part of that country. For example, if many people leave the small communities and go to live in the city, then this will cause the population of the city to increase. Do you know anyone who left a small community and went to live in a town or city?

People also migrate from one country to another. Sometimes people leave other countries and come to live in your country. When people move into a country to live this is called immigration. Immigration can cause the population to increase. People who move into a country are called immigrants.

Sometimes people leave their country and go to live in another country. When people move out of a country, this is called emigration. Emigration can slow down population growth or even cause the population to decrease. People who move out of their country are called emigrants.

^{Some people leave their home country and go to live in another country.} 

Do you know anyone who left your country and went to live in another country?

Quick facts

• The population of a country will most likely grow if the number of babies born is greater than the number of people who die. 
• If immigration is higher than emigration, this is likely to cause the population to grow.
• If Drecia leaves St. Lucia and goes to live in England we can say that she emigrated from St. Lucia and immigrated to England.

Quick question

• What will happen to the population of a country if the number of deaths is greater than the number of births AND the number of emigrants is higher than the number of immigrants?