The factors driving mainland Chinese to study in the United States come into play much earlier, Lin said, noting an influx of foreign Chinese students into private U.S. secondary schools, starting around 2005.

Chinese parents send their children to private U.S. high schools as a "strategic decision" to strengthen their candidacy for elite U.S. universities, Lin said. A growing number also want their children to lead happier lives rather than have them consumed by preparing for the "gaokao" in China -- the one-time, high-stakes national university entrance examination that is the sole determinant of admission.

"The goal of education in mainland China is to prepare you to take the gaokao. Everything else is secondary. In China, you would put the gaokao in the center...whereas...in American education, you put the student in the center, and everything else serves the best interests of the student. It's not exclusively about (getting into) college."

While U.S. boarding schools desire Chinese students both for their dollars and diversity, they walk a "very fine line...when it comes to recruiting Chinese students," said Lin, who assisted with admissions during his tenure teaching at Connecticut's Cheshire Academy.

Boarding schools typically admit four to five students of any foreign nationality per grade level, with international students comprising up to 20% of the overall student body, Lin said. With about 100 students for each of the four grade levels, this means admitting a maximum of 20 mainland Chinese, or five percent of the student body.

"A school could easily fill itself with all Chinese students, but no school's going to do that...It's a double-edged sword -- if you have too many Chinese, then the Chinese will stop coming to your school, and also, Americans will stop coming to your school."

Driving international enrollment at U.S. universities

By virtue of their size, U.S. universities can accept a much higher number of Chinese students than boarding schools.

Since 1999, China was the second leading place of origin for international students at Harvard, trailing only Canada. Its student numbers steadily increased to lead Harvard's international enrollment since the last academic year, with 686 students currently enrolled (nearly 16% of the international student body.)

China similarly dominates international enrollment at other Ivy League schools, including Yale and Princeton.