For labor-intensive enterprises in China, the shortage of labor, which has been noticeable for a few years, continues to be a headache. But at the same time many migrant workers in their 40s and 50s are finding it increasingly difficult to get a job.

A typical example is Zhao Zhongwei from Shandong province, who had to hide his real age to keep his job as a repairman.

The problem is a high percentage of China's labor force has reached the middle age now, but manufacturing does not favor these migrant workers as the performance of manual laborers declines with age, said Zhang Zheng, a researcher with the Guanghua School of Management at Peking University.