This past May, as Southern Californians entered their third month in quarantine from Covid-19, the local affiliate of PBS premiered a new documentary about poverty in China. Promising “unprecedented access,” the hour-long film followed Robert Lawrence Kuhn, a brain scientist and investment banker-turned-documentarian, as he traveled around China’s impoverished countryside. In his trademark mock turtlenecks, Kuhn interviewed villagers and officials about Beijing’s anti-poverty program — a massive effort that intends to lift 100 million people out of abject poverty.  “President Xi Jinping,” the trailer’s narrator said knowingly, “is counting on its success.”  Kuhn has a limited grasp of Mandarin, but he seems at home in the film. With his glasses, thin frame, and shock of white hair, the 75-year-old rides on the back of motorbikes, walks through murky rivers, and sits on plastic chairs with local government officials. The documentary — entitled “Vo