This is protectionism of another sort: Some cities, in the thick of a most dangerous economic crisis across the world, are trying to protect the local jobs at the expense of job market equality.

It would be a mistake if national trade unions and the central government's labor authorities fail to act promptly to halt the toxic tendency among some relatively affluent cities to try to shield their local job markets from the migrant workers.

According to central government data, up to 20 million migrant workers have lost their urban jobs.