The document defines key economic terms related to employment, unemployment, inflation, and interest rates. It defines who is employed, unemployed, and not in the labor force. The unemployment rate is the ratio of unemployed to the labor force. The labor force participation rate is the ratio of the labor force to the total population. Unemployment can be frictional, structural, cyclical, or the natural rate. Inflation is a sustained increase in prices, and can be demand-pull or cost-push. Deflation is a fall in prices. Producer Price Indexes track prices at different production stages. The real interest rate is the difference between the nominal interest rate and inflation rate.