Immigration is a good thing : open the borders

A policy that's worked extremely well in Europe and should indeed be adopted more widely.

Economist Michael Clemens estimates that the economic gains from worldwide open borders are large enough to double world GDP. Enormous numbers of people currently live in poverty not because they are unable to be productive workers, but merely because they are forcibly prevented from working for First World employers who would be willing to hire them. 

Many potential migrants are also trapped in societies where they are denied basic human rights, such as freedom of speech, religion, and private property. Many of the women among them reside in societies with severe gender-based oppression and discrimination. For hundreds of millions of people living in undemocratic societies, emigration is their only realistically feasible way to exercise political freedom – the right to choose what kind of government they wish to live under.

Perhaps most important, immigration restrictions are severe infringements on individual freedom in and of themselves. They forbid people to live and work where they wish purely based on arbitrary circumstances of birth for which they are not responsible. They also restrict the liberties of native-born citizens who wish to engage in economic and social transactions with migrants.

The United States in fact had virtually complete open borders until the enactment of the racist Chinese Exclusion Act of 1882, and open borders for nearly all non-Asian immigrants until the 1920s. If today’s more restrictionist policies had been followed in the first 130 years of American history, the ancestors of most Americans would never have been allowed to enter the country.

https://www.washingtonpost.com/news/volokh-conspiracy/wp/2014/03/16/open-borders-day/?noredirect=on&utm_term=.9dcdef483e0e