Is it a good idea? Immigration is one of the issues most hotly debated by politicians at election time. Some believe the answer is to let people come and go as they please.
The big idea: A world with no national borders
Global migration: Nearly 10,500 people have crossed the English Channel so far in 2024. Glossary
Net migration - The difference between the number of people moving into a country (immigrants) and the number of people leaving the country (emigrants).
Statue of Liberty - A joint French-American project, finished in 1886, the statue celebrates the abolition of slavery and international friendship. Its original name was Liberty Enlightening the World.
GDP - Short for Gross Domestic Product, the measure of all the goods and services produced inside a country.