The Dandelion School educates children of migrant workers, refugees from peasant villages in central China who are vying for crumbs from Beijing's economic boom. Outside the school walls, they are heading to work as maids, laborers, and factory workers. For the children, this is a rare shot at upward mobility. Dandelion is among hundreds of private institutions set up in the past two decades to educate China's estimated 20 million school-age migrant children, who until recently were barred from attending school in their adopted cities and still face many barriers to admission, including financial ones.