At this very moment, in a major Chinese city, a worker is boarding a train home. His journey is just one of 3.4 billion trips that will be taken during China's Lunar New Year. An unprecedented number of Chinese will travel home this year to be with family and friends during the holiday, making it the world's largest annual migration of people. Their yearly homecoming has been repeated over and over for the past two decades, reuniting families in the villages with the workers who have fueled China's economic miracle. But that growth has come at a tremendous personal cost thanks in part to a household registration system called "hukou. "In effect, the hukou system now only targets the poor."