From the summary:
Relative to any of the most common benchmarks – the cost of living, the wages of the average worker, or average productivity levels – the current federal minimum wage of $7.25 per hour is well below its historical value. These usual reference points, however, understate the true erosion in the minimum wage in recent decades because the average low-wage worker today is both older and much better educated than the average low-wage worker was in the past….
…Between 1979 and 2011, the average age of low-wage workers (defined as earning $10.00 per hour or less in 2011 dollars) increased 2.3 years, from 32.3 to 34.9… [T]he rise in the average age reflects a big drop in the share of low-wage workers who are teenagers – from over one-in-four (26.0 percent) in 1979 to less than one-in-eight (12.0 percent) in 2011….
The educational attainment of low-wage workers has also soared. As the next figure demonstrates, the share of low-wage workers with some college education (but not a four-year degree) rose dramatically, from about one-in-five (19.5 percent) in 1979 to one-in-three (33.3 percent) in 2011. By 2011, almost one-tenth (9.9 percent) of low-wage workers had a four-year college degree or more, up from 5.7 percent in 1979. And the share with less than a high-school degree dropped by almost half, from 39.5 percent in 1979 to only 19.8 percent in 2011….