Econometric models are used by economists to find standard relationships among aspects of the macroeconomy and use those relationships to predict the effects of certain events (like government policies) on inflation, unemployment, growth, etc... Econometric models generally have a short-run aggregate supply component with fixed prices, and aggregate demand portion, and a potential output component. Two famous econometric models are the Federal Reserve Bank econometric model and the DRI-WEFA model. This book presents new and important research in this field.