According to the International Labor Organization, an individual is unemployed if they are not working in the reference period, available and willing to work, and are actively seeking employment. In the United States, for example, the Bureau of Labor Statistics reference period used for actively seeking work is in the last four weeks. An individual is defined as employed if they have worked for pay for at least one hour, or are self-employed during the reference period. The labor force is comprised of employed and unemployed individuals. The unemployment rate is the fraction of the labor force that is unemployed. Individuals can become unemployed because they enter the labor force and it takes time to find a job, or because they leave employment. In the ...