The labor force is the number of people ages 16 or older who are either working or looking for work. It does not include active-duty military personnel or the institutionalized population, such as prison inmates. Determining the size of the labor force is a way of determining how big the economy can get. The size of the labor force depends on two factors. The first is the size of the population, which is determined by rates of birth, immigration, and death. The second is the labor force participation rate--the percent of the population that is working or actively seeking employment. Labor force participation rates vary significantly between men and women and among different age, racial, and ethnic groups. Population growth rates also vary from one group to another. These variations change the composition of the labor force over time. This paper presents charts that show how the labor force is projected to change among age groups, between men and women, among racial groups (Asians, blacks, whites, and others), and among ethnic groups (Hispanics and non-Hispanics of any race). The U.S. Census Bureau uses these categories to produce the demographic data on which BLS projections are based.