David Oxtoby, president emeritus of Pomona College (CA) and a president in residence at the Harvard Graduate School of Education, and Nancy Cantor, chancellor of Rutgers University at Newark (NJ), write:  Over the years, higher education has played a major role in immigration. Colleges and universities, which have brought young people from overseas to this country as undergraduates and graduate students, have helped them become highly productive members of society. Many stay after receiving their degrees to take jobs or to start up new ventures. Such immigrants are more than twice as likely as U.S.-born citizens to establish new businesses, including many at the cutting edge of technology.