From the study:
Averaged across all occupations, we estimate that real median wages declined by 2.8 percent from 2009 to 2012. This is a striking decline, given that productivity increased by 4.5 percent over this same time period....Moreover, as shown in Figure 1, lower-wage and mid-wage occupations saw significantly bigger declines in their real wages than did higher-wage occupations. Occupations in the top two quintiles saw their median wages decline by less than 2 percent on average (and nearly a third of those occupations actually saw real wage growth). By contrast, occupations in the bottom three quintiles saw their median wages decline by 3 percent or more.
Keep in mind that the recession officially ended in June 2009, so these wage losses are all coming during the period that we laughably refer to as a "recovery." Some recovery.