The labor force is the amount of people in an economy either employed or actively looking for employment. In the United States we see this as between 58% and 65% of the population at any given time. This is also the number used to calculate the unemployment rate. Unemployment rate is the number of people looking for a job, divided by the total number of people in the labor force. The labor force is constantly shifting in size. When a student leaves college and begins to look for a job, the labor force expands; when a mother decides to stay home with her kids full-time, the labor force contracts. The relationship between the labor force and unemployment leads to unique situation. If people who are unemployed decide to give up looking for a job the unemployment rate will actually go down. This is why multiple analytical economic statistics are used to compare economies. It is not a stretch to assume going from looking for a job to giving up looking for a job is a decrease in the economic vitality of that individual, yet the macroeconomic indicator of gainful employment, the unemployment rate, shows an increase in the individual economic welfare of people in the economy, if that person gives up looking for a job. We actually saw a decrease in the labor force in the past few years, which could partially explain the decrease in unemployment. The labor force, and its growth, is necessary for a strong economy. Labor force could be seen as the equivalent of investment when it comes to economic prosperity; this is because both labor and capital are input for the production function to calculate GDP. While the labor force is constantly changing, its importance is not.