One major concern since the start of the recent recession has been the labor force participation rate. The graph above shows a clear and continuing decline. However, when you reveal the full sample, as shown in the graph below, you can see the decline started before the recession and the current level is not the lowest in postwar history. It appears, then, at least part of the current evolution of labor force participation has to do with a longer-term trend. What forces are at work here? Clearly, the rise in labor force participation had to do with many women entering the labor force. The subsequent decline has to do with the aging of the population, with a significant increase in the proportion of retirees. Also, the younger population is staying in school longer than before. Articles by Marianna Kudlyak and Maria Canon and Marianna Kudlyak provide more insight on this topic.
Source: FRED Blog