For all their importance, there's little consensus on what the college rankings actually mean.
In 1999, Yongjun Huang was graduating from high school in Xindu, China, and looking to study mechanical engineering. Now a Georgia Tech graduate, he says he "compared dozens of schools" in China and the US with the only tools available: "traditional reputation" and the college rankings in US News & World Report and the Princeton Review.
But by the time another young Xindu student was looking to study abroad in 2009, the rankings industry had boomed, says Qiuyun Wang, whose parents expected her "to go to a world-famous college." A dozen rankings focused solely on the US and about 10 compared universities around the globe.
The Huangs and the Wangs aren't the only ones who care about the ratings. When the US lost four slots in the top 200 of the Times Higher Education World University Rankings, and Asia claimed five more spots in 2009, headline writers were quick to declare the US was losing dominance in higher education. Universities and colleges monitor rankings as carefully as TV networks monitor the Nielsens, and when institutions seek partners for joint programs or exchanges, they check to make sure they don't marry down.