According to the Congressional Budget Office there are several (structural) reasons which led to a decrease in the labor force participation rate in the United States, besides the economic crisis.
- Long term trend for people between 16-24 to study more and work less while studying.
- The Baby boom elderly population starts to retire.
- In november most of the drop in the participation rate was driven by unmarried woman. The share of woman who chose to work fell to its lowest level in 20 years.
Ofcourse these causes may well be strengthened by the economic crisis and its important not to forget the United States unemployment is still at a record high. Although lower than the unemployment of the European Union.