Humans are no newcomers to migration. Early human migrations are thought to have begun when Homo erectus first migrated out of Africa to Eurasia around 1.8 million years ago.

Nowadays, the largest migration corridor in the world is Mexico – USA, with almost 12 million official recorded migrations from Mexico to the US in 2010 alone. In fact, in 2006 the USA took in more legal immigrants as permanent residents than all the other countries in the world combined. Ironically, if a Mexican wants a visa to migrate to the United States, they must obtain it in Ciudad Juarez, undoubtedly one of the most violent and dangerous cities in the world. 

When it comes to the UK, most people emigrating from the country go to Australia, followed by the USA. British people mostly choose Australia, because it is an English‑speaking country, and they don’t need a visa to get there. Other important factors are the warm climate and the work‑life balance. As for the immigration to the UK, most migrants come from India, then Poland, and Pakistan in third place. Most of the non‑EU migrants come to the UK to join their families, while the most of the EU migrants come searching for employment. On balance, the United Kingdom is home to the most diverse migrant community in the world.

One of the countries with the largest number of immigrants is the United Arab Emirates. It has the highest share of foreign‑born people (88% of its population). The majority of them come from South Asia, with approximately 38% from India. The Emiratis constitute only about 12% of the population.

On balance, it might be said that countries with the fewest resources send lower shares of migrants, while the middle‑income countries send most migrants. According to the Migration and Remittances Factbook 2011, approximately 3% of the world population (more than 215 million people) live in a country other than the one they were born in. Surprisingly, though, relative to world population size, more people were migrating around the end of the 19th century than they are now.