To glimpse how migration is changing the world, consider Western Union, a fixture of American lore that went bankrupt selling telegrams but now earns nearly $1 billion a year helping poor migrants across the globe send money home.

John Tanton is the Johnny Appleseed of the anti-immigration movement. Rarely has an individual done more to build a grassroots movement or done it so far from the public eye.

Migrant workers from the Philippines send billions back to their families. But as the multigenerational saga of Rosalie Villanueva and her family shows, the human costs are harder to calculate. In her family, a good provider is one who leaves.

Nepal’s per capita income looks like a misprint: $270 a year. If rich countries want to help, says Harvard economist Lant Pritchett, they should admit more Nepali workers.

Cork-born and proud of it, George-Jordan Dimbo is top to toe the Irish lad. But his parents are undocumented Nigerian immigrants, and his story has millions of parallels in the United States.

No one has done more to make migration and its potential rewards a top-of-the-agenda concern than the World Bank economist Dilip Ratha. He grew in the isolated village of Sindhekela, where monkeys prowl rutted roads, and the native son who achieved the most did so by going away.

Across the globe, migrants move to poor countries nearly as often as they move to rich ones. Haitians’ movement to the Dominican Republic has been large, longstanding and filled with strife.