For thousands of years, people have moved to new places. This movement is called migration. Immigrants are people who move into one country from another.
Some people choose to move. This is called voluntary migration. Today, most people move by their own choice. The push-pull theory explains voluntary migration. It says that difficulties push people to leave. At the same time, the hope for a better life pulls them to a new country.
Here is an example of the push-pull theory. Many years ago, 1.5 million people left Ireland for the United States. Disease had destroyed Irelands main crop, potatoes. Hunger pushed people to migrate. Job opportunities pulled Irish families to the United States.
Today, the main sources of migration are countries where many people are poor or there are few jobs. Sometimes, wars have made life dangerous and difficult. Also, some governments limit peoples freedom. These problems push people to leave. They are pulled by the possibility of good jobs or political freedom.
Sometimes people are forced to move. This is known as involuntary migration. In the 1800s, the British sent prisoners to Australia to serve their sentences. War also forces people to migrate to escape death or danger.
The biggest involuntary migration may have been the slave trade. From the 1500s to the 1800s, millions of Africans were enslaved and taken to European colonies in North and South America.
Millions of people in many countries have moved to cities from farms and small villages. As a result, some cities have grown enormously in recent years. The movement of people to cities and the growth of cities is called urbanization.
In Europe and North America, the growth of industry created jobs. People moved to cities for jobs in factories and offices. Today, people in Europe and North America are moving out of cities into suburbs. Most people in suburbs rely on cars for transportation. More cars mean increased pollution. But people still move to suburbs so they can own homes.
In Asia, Africa, and Latin America, people are still moving from the countryside to growing cities. Indonesia is an example. In the past, people lived in ruralareas. Recently, many Indonesians have moved to urbanareas. The capital has grown from 3.9 million people to 11 million people in thirty years.
Often, too many people are moving to the city too fast. Cities cannot provide the things that people need. There are shortages of housing, jobs, schools, and hospitals.
So why do people move to big cities? As hard as life is in the cities, it can be even harder in the countryside. Often, there are few jobs and not enough farmland. Most migrants who move to the city want a better life for their families.