A new survey shows that the real unemployment rate in China is double the official level, and layoffs rose sharply among migrant workers in the past year, underlining a challenge for China's new leaders to maintain growth. The survey of 8,000 households shows the urban unemployment rate hit 8.05% in June, up slightly from 8% in August 2011 and nearly twice as high as the official 4.1% rate. The survey was run by Gan Li, an economics professor at South Western University of Finance and Economics in Chengdu.