A person can make up to ten times more money in a rich country compared to if he/she was doing identical work in a lower-income country. This "location premium" reflects the gains to workers' income just from migration. But restrictions to labor mobility persist around the world, with reasons ranging from physical security to job protection of native workers. The economic literature is full of evidence suggesting massive gains to the migrant workers and their destination countries, but new arguments claim to show an efficiency case can be made for limiting labor mobility. Michael Clemens of the Center for Global Development talks with us on this episode about the economic arguments for and against migration restrictions.