The Fourteenth Amendment to the United States Constitution guarantees U.S. citizenship to those born on its territory, provided the person is "subject to the jurisdiction" of the United States.
This practice is believed to be popular among women in India,South Korea,China Hong Kong, and Taiwan. The practice is popular among the elite and wealthy circles of these countries. Temporary homes for these mothers are often located in residential neighborhoods, which neighbours allege decrease the quality of life in the neighborhood, primarily due to increases in traffic and other business-like effects. It's easy. If you register the birth, it's automatic that your baby can get an American passport. :)
Reasons even a fool can told u -
1. Free Citizenship
2. Free Education (public education in US is free)