China Union Expands at McDonald's

Recently, All China Federation of Trade Union continued researching foreign companies' minimum wage for Chinese workers, such as McDonald's Corp. and Yum Brands Inc. Based on the survey, we found that these foreign companies minimums wage for Chinese workers were lower. For example, the minimum wage for student workers is 7.5 Yuan, or about 97 US cents an hour.
Why did these foreign companies give Chinese workers such a lower wage? On the one hand, Chinese cheap labor lead to a max profit for these foreign companies. Reducing workers' wage equals decreasing the variable cost. Then the total cost will decrease. Finally, the profit will increase, and by this way these companies can make max profit. As we know, many foreign companies like to invest in China just because of Chinese cheap labor; of course, Chinese cheap labor can let them get more profit.
On the other hand, this news makes me think of America wanting China to increase exchange rate. In my opinion, owing to Chinese cheap labor, products that are made in China are cheaper than other counties. As a result, consumers like to buy these products made in China, and then the same products which made in other countries would lose consumers. It leads to imbalance. Therefore, America and many foreign companies want China to increase its exchange rate so that products made in China would increase its price. Eventually, the prices of China's products are the same as others.