NEW YORK -- Ever since national frontiers were invented, people have been crossing them -- not just to visit foreign countries, but to live and work there. In doing so, they have almost always taken risks, driven by a determination to overcome adversity and to live a better life.
Those aspirations have always been the motors of human progress. Historically, migration has improved the well-being not only of individual migrants but of humanity as a whole.
And that is still true. In a report that I presented last week to the U.N. General Assembly, I summarize research showing that migration, at least in the best cases, benefits not only the migrants themselves but also the countries that receive them, and even the countries they have left. How so?