Each year, the United States approves more than a million immigrants for permanent residency or green cards. For decades, more than half of immigration to our country has been chain migration — immigrants sponsored by a family member who came earlier, most often a new spouse, a grown son or daughter, or a sibling. In contrast, only about 15% of annual immigration is based on skills or sponsorship by an employer, with the remainder based on a green card lottery or humanitarian programs.

Studies show that, aside from nuclear family members who are admitted at the same time, new immigrants sponsor an average of 3.45 additional family members who come later. Immigrants from some top-sending countries, such as Mexico, India, the Philippines, and China, tend to produce even more chain migration, with a multiplier of more than five additional sponsored immigrants per newcomer.