At last the map was finished. Called Wild World, it had taken Anton Thomas three years to draw and included pictures of 1,642 animals. There was something else special about it too: it contained no human-drawn borders. 

Many of the elections being held around the world this year have immigration high on the agenda. Britain's prime minister Rishi Sunak says that he is determined to stop the small boats carrying illegal migrants across the Channel. He is also determined to send unwelcome newcomers to Rwanda.

Labour's Keir Starmer has promised to make border policing more efficient. Reform's Nigel Farage says he wants to reduce net migrationThe difference between the number of people moving into a country (immigrants) and the number of people leaving the country (emigrants). to zero.

But there are those who believe that restricting immigration is wrong, that national borders should be abolished altogether.

Economist Alex Tabarrok says that most people who live in a rich country do so because they were lucky enough to be born there, and that this does not give them more of a right to enjoy its benefits than people born elsewhere.

He adds that immigrants bring new skills and help an economy.

Is it a good idea?

Yes! It is incredibly unfair that some people have miserable lives just because they were born in a poor country rather than a rich one.  

No! There would be chaos. According to Gallup, 15% of adults - over 750 million - would move to another country if they could.