Cyclical unemployment refers to select one: a. The portion of unemployment created by job search. b. Short-run fluctuations around the natural rate of unemployment. c. Changes in unemployment due to changes in the natural rate of unemployment. d. The portion of unemployment created by wages set above the equilibrium level.

b. Short-run fluctuations around the natural rate of unemployment.

Extra: Cyclical unemployment is a concept from economics that refers to the fluctuating unemployment rate due to changes in the economic cycle. When the economy is in a boom, or expansion phase, cyclical unemployment tends to decrease because businesses are growing and hiring more workers. Conversely, during a recession or contraction phase, cyclical unemployment increases as businesses lay off workers due to decreased demand for products and services.

This concept is different from other types of unemployment, such as:

- Frictional unemployment (option a), which is associated with the time period individuals spend searching for a job or transitioning from one job to another.

- Structural unemployment (option c), which occurs when there is a mismatch between the skills workers possess and the skills needed for the available jobs, often due to technological changes or shifts in the economy.

- Classical or real-wage unemployment (option d), which is when wages are artificially kept above the market-clearing level, preventing supply and demand from meeting. This can be due to minimum wage laws, labor unions, or other wage-setting mechanisms.

Understanding cyclical unemployment is important for policy-makers who use fiscal and monetary tools to try to smooth out the economic cycle and reduce the negative effects of recessions on workers. It's also crucial for economists who are trying to measure the health of the economy or predict future trends.