Final answer:
Frictional unemployment arises when workers are between jobs, searching for employment that matches their skills and preferences. It is part of the natural rate of unemployment and remains even in a healthy economy. The correct answer is natural rate of unemployment.
Step-by-step explanation:
Unemployment that results because it takes time for workers to search for the jobs that best suit their tastes and skills is called frictional unemployment. This type of unemployment is part of the natural rate of unemployment, which includes both frictional and structural unemployment.
Frictional unemployment is not considered negative as it reflects the time needed for workers and employers to find a suitable match for their requirements. It is a naturally occurring result of the job search process in a dynamic labor market. Unlike cyclical unemployment, which is dependent on the business cycle and economic downturns, frictional and structural unemployment constitute the base level of unemployment that exists even in a healthy economy.