In this survey, only 31 (10 percent) of 302 respondents considered minimum wage increases to have had a "huge" impact.

However, just over half said that the hikes have forced them to raise wages more than they had planned. The bank's survey had the same results in 2012, suggesting that minimum wage hikes have had a significant cumulative effect, particularly on the least-skilled part of the workforce.

"We note, though, that 103 (37 percent) respondents think their wages would have risen even without the hike in the required minimum," said Green.

A total of 11 provinces and cities have already announced minimum wage hikes this year. The average increase has been about 16 percent. Shenzhen has the highest wages for migrant workers in the country at 1,600 yuan a month. According to the Ministry of Human Resources and Social Security, a total of 25 provinces adjusted their minimum wages last year by an average of 20.2 percent.