… is from page 75 of Julian Simon’s 1993 essay “In Favour of Immigration,” as reprinted in the splendid 2000 collection Population: The Ultimate Resource (Barun S. Mitra, editor):
Opponents of immigration seek to persuade us that new immigrants damage society economically, politically, and culturally. Immigration restrictions are intended to “protect us” in the same way as tariffs and trade quotas. But like trade barriers, immigration restrictions largely protect us from benefits. This is not to say that immigration brings no adjustment costs. But historical and current evidence shows that the costs are exaggerated and the benefits vastly under-appreciated.