In the next 50 years, demographic changes will significantly alter the U.S. population and labor force. These changes include an aging and more diverse population that will continue growing, but at a slower rate. These changes will impact the growth of the U.S. economy and its ability to create goods and services.
The growth of the labor force is directly related to the growth of the population and changes in the labor force participation rate. A significant part of the changes in labor force growth results from changes in the population. The labor force participation rate has declined substantially since its peak in 2000, for both demographic and economic reasons.
Ref: A look at the future of the U.S. labor force to 2060. U.S. Bureau of Labor Statistics (September 2016) | PDF