Berlin's Humboldt University — named for its founder, the 19th century philosopher and linguist Wilhelm von Humboldt, and his brother, naturalist Alexander von Humboldt, pictured here — is one of several German universities attracting U.S. students. More than 4,000 Americans are studying in German universities. Markus Schreiber/AP hide caption

itoggle caption Markus Schreiber/AP

During the fiscal years 2003-2012, "median tuition rose 55 percent across all public colleges," while state funding decreased by 12 percent, the General Accountability Office reports. Imeh Akpanudosen/Getty Images hide caption

itoggle caption Imeh Akpanudosen/Getty Images