economic output. The supply of labor depends on the size of a country’s population and the country’s labor force participation rate.
A country’s population size can be affected by its fertility rate, life expectancy, and international migration. In 2012, the fertility rate in the United States was the lowest since data collection began in 1920.
But life expectancy at birth has been rising for a century or more, while the population has increased because of international migration.
In the United States, the labor force participation rate for men has been falling for several decades. The participation rate for women increased for several decades until 1999, but has fallen since..."
Undeveloped labor supply