When Republican Senate candidates in Missouri were recently asked if they would raise the minimum wage, two out of three of them trotted out versions of the claim that the minimum wage is for teenagers who aren't worth more and wouldn't be able to find work if employers were required to pay them more. That's a common claim from proponents of a rock-bottom minimum wage (or even none at all), and it's wrong—a majority of minimum wage earners are adults. Not only that, but the Center for Economic and Policy Research's John Schmitt and Janelle Jones show that low-wage workers, defined as those earning $10 an hour or less (in 2011 dollars), were a much older and more educated group in 2011 than they were in 1979.

In 1979, more than a quarter of low-wage workers were teenagers. By 2011, it was cut by more than half, down to 12 percent. The only other age group that lost even a tiny a share of low-wage workers in those years was people 65 and over, who went from 4.6 percent of the low-wage workforce to 4.2 percent. Every other group—meaning people in their prime working years—grew as a percentage of the low-wage workforce. People ages 35 to 64, in particular, shot from 30.8 percent to 38.1 percent of workers earning $10 an hour or less.

Low-wage workers today are not just older than in 1979, they're also better educated. The percentage who have not graduated from high school has been cut by nearly half; those with some college education, but not a four-year degree, shot up from 19.5 percent to 33.3 percent. Nearly one in 10 people earning $10 or less has a college degree, or more. And it's certainly not as if these low wages are going further than they did in 1979.

Each of these statistics points to a single fact: The American low-wage workforce has gotten older and better educated during three decades in which the value of the minimum wage has dropped. These statistics are signs of the increasing difficulty of even making a sustainable living, never mind getting ahead or living the American Dream. Yet we still constantly hear Republicans invoking the group in that workforce that's shrinking—inexperienced teenagers. The reason is simple: Republicans aren't concerned with reality. They're just concerned with keeping wages low so companies can squeeze higher profits out of workers.