Chinese President Hu Jintao concluded his four-day U.S. tour on Friday with a visit to Yale University in New Haven, Connecticut, where he sought to lower fears about the international effects of his country's booming economy and pledged continued cooperation with the United States. Yale president Richard Levin met privately Friday morning with Hu before the Chinese leader delivered a public speech and answered two questions from the audience. Asked whether China was concerned that limiting political freedom would cause social unrest that could undermine economic growth, Hu responded that China is committed to democracy. “China's political system suits its economic development,” he said. Several blocks away, hundreds of protestors waved signs and shouted anti-communist and anti-government slogans in Chinese. Yale has long had ties to China. In the 1800s, it was the first U.S. university to graduate a Chinese student, and it now has more than 80 academic collaborations with Chinese institutions and offers 26 study sites in China.