11. Frictional unemployment reflects the time required for potential workers to find suitable jobs and for firms with vacancies to find suitable workers. Structural unemployment-long-term and chronic unemployment that exists even when the economy is not in recession-occurs because some workers do not have the skills needed to obtain long-term employment or because of delays in reallocating workers from economically depressed areas to those that are growing. Frictional and structural unemploy- ment together account for the natural rate of unemployment, which is the unemployment rate that exists when employment is at its full-employment level. Cyclical unemployment is the excess of the actual unemployment rate over the natural rate of unemployment.