The document discusses the natural rate of unemployment and its causes. It is made up of frictional unemployment, which occurs due to the time needed to search for suitable jobs, and structural unemployment, which happens when wages are kept above the equilibrium level. This can be due to minimum wage laws, unions bargaining for higher wages than the market equilibrium, and efficiency wages, where firms voluntarily pay above market wages to boost productivity. The natural rate of unemployment is normal for a healthy economy, while cyclical unemployment rises above it during recessions.