Unemployment is defined as a situation when an employed person is laid off, fired or quits his work and is still looking for a job. Even in a healthy economy unemployment occurs. If former employed persons go back to school or leave the job to take care of children they are no longer part of the active labor force and therefore not among the unemployed.
Unemployment can also be the effect of events that are not part of the normal dynamics of an economy. Layoffs can be the result of technological progress, for example when robots replace workers in automobile production. Sometimes unemployment is caused by job outsourcing, due to the fact that employers often search for cheap labor around the globe and not only domestically. A rise in unemployment was also an effect of the financial crisis that hit the United States in 2008.
The unemployment rate in the United States varies from state to state. The state with the highest number of unemployed persons in the United States in 2017 was California. Around 919,000 unemployed persons were counted in California.