Minimum wage has not tracked productivity. People who must rely on these paltry wages are living at near-poverty level and with high unemployment and weak worker rights, it is difficult to demand fair compensation from employers.

http://www.peri.umass.edu/fileadmin/pdf/resources/Minimum_Wa...

>In 1968, the real value of the minimum wage was $10.65, so that, in fact, an increase today to a $10.50 federal minimum would not even bring the minimum wage fully back to the 1968 standard. Moreover, since 1968, average U.S. labor productivity has risen by 135 percent. Thus, if, since 1968, the U.S. minimum wage had only just kept up with inflation and average labor productivity growth, the minimum wage today would be $25.00.