Ch. 10: Aggregate Supply and Demand Derive AS/AD model Understand cause & consequences of change in AS/AD Short run vs Long run Effects on economic growth, prices, unemployment. Different schools of thought in macroeconomics

Macroeconomic Long Run and Short Run The Macroeconomic LR a time frame that is sufficiently long for the real wage rate to have adjusted to achieve full employment: Real GDP = potential GDP. Unemployment=natural unemployment rate. Price level determined by quantity of money (equation of exchange) Inflation rate =money growth rate minus the real GDP growth rate. The Macroeconomic SR a period during which some prices are sticky so Real GDP might be below, above, or at potential GDP. The unemployment rate might be above, below, or at the natural unemployment rate

Aggregate Supply The quantity of real GDP supplied is the total quantity that firms plan to produce during a given period. It depends on The quantity of the labor employed The quantity of physical and human capital State of technology Two time frames associated with different states of the labor market: Long-run aggregate supply Short-run aggregate supply

Aggregate Supply Long-Run Aggregate Supply (LAS) the relationship between the quantity of real GDP supplied and the price level when real GDP equals potential GDP. Potential GDP is determined by Production function Labor market Independent of price level LR aggregate supply curve (LAS) is vertical at potential GDP.

Determinants of LAS Labor market LAS Production function

Determinants of LAS Change in labor supply Change in labor demand immigration taxes on employees transfers (UI, SS) population growth retirement Change in labor demand worker productivity (also affects PF) taxes on employer payroll Shifts in Production Function capital/technology (also affects LD) human capital

Graphic analysis of changes in LAS (Change in Labor Supply) Effect on Real wage Employment productivity

Graphic analysis of changes in LAS (change in Labor Demand) Effect on Real wage Employment Productivity

Graphic analysis of changes in LAS (Change in Production Function) Effect on Real wage Employment productivity

Aggregate Supply Short-Run Aggregate Supply (SAS) the relationship between real GDP supplied and the price level when the money wage rate, the prices of other resources, and potential GDP remain constant. A rise in the price level with no change in the money wage rate and other factor prices increases the quantity of real GDP supplied. as P rises, real wage declines, firms want to hire more employees (movement along labor demand curve) The short-run aggregate supply curve (SAS) is upward sloping.

Short Run Aggregate Supply Labor market SAS Production function

Aggregate Supply Along the SAS curve, real GDP supplied might be above potential GDP… or below potential GDP.

Aggregate Supply Changes in Aggregate Supply When potential GDP increases, both the LAS and SAS curves shift rightward. Potential GDP changes, for three reasons: The full-employment quantity of labor changes The quantity of capital (physical or human) changes Technology advances

Aggregate Supply An increase in potential GDP shifts the LAS curve and the SAS curve shifts along with the LAS curve.

Aggregate Supply A rise in the money wage rate Decreases short-run aggregate supply and shifts the SAS curve leftward. Has no effect on long- run aggregate supply.

Falling; rising; falling. Falling; rising; rising. In the short run, if the economy moves upward along the SAS curve, prices are ____, real wages are _____ and real GDP is _____. Falling; rising; falling. Falling; rising; rising. Rises; rising; rising. Rising; falling; rising. 30

Aggregate Demand AD is the total amount of final goods and services produced in the United States that people, businesses, governments, and foreigners plan to buy. AD= C + I + G + (X – M.) AD depends on The price level Expectations about future Changes in wealth Fiscal policy and monetary policy The world economy

Aggregate Demand The Aggregate Demand Curve plots the quantity of real GDP demanded against P. slopes downward for 2 reasons: Wealth effect Substitution effects

Aggregate Demand Wealth Effect P increases  real wealth decr  C decr  AD decr Substitution Effects Intertemporal P incr  int rate incr  C & I decr  AD decr International P incr  imports incr, exports decr  AD decr

Shifts in Aggregate Demand Expectations about future Increases in expected future income  increases C today  increases AD. Increase in expected future inflation  buying goods cheaper today  increases AD. Increase in expected future profits investment  increases AD

Shifts in Aggregate Demand Fiscal Policy setting and changing taxes, transfer payments, and purchasing goods and services. An income tax cut or increase in transfers  increases disposable income (income-taxes+ transfers)  increases C  increases AD An increase in government spending  increases G  increases AD

Shifts in Aggregate Demand Monetary policy changes in interest rates and the quantity of money in the economy. An increase in the money supply reduces interest rates and increases aggregate demand.

Shifts in Aggregate Demand Summary: Fiscal policy Monetary policy Value of $ Foreign income

Macroeconomic Equilibrium SR Equilibrium: SAS=AD GDP can be above, below, or at potential GDP LR equilibrium LAS=SAS=AD

Macroeconomic Equilibrium Graphical illustration of SR equilibria with GDP>potential GDP (inflationary gap) 2. GDP<potential GDP (recessionary gap) 3. GDP=potential GDP (LR equilibrium)

SAS shifts left until GDP=potential GDP Transition from GDP>potential GDP to LR equilibrium (inflationary gap) Initially: empl > equil. Empl unempl < natural rate R-wage < equil. R-wage upward pressure on R-waqes SAS shifts left until GDP=potential GDP As economy moves to LR Equilibrium: Employment falls, Unemployment rises, Real wage rises, Real GDP falls

SAS shifts left until GDP=potential GDP Transition from GDP<potential GDP to LR equilibrium (recessionary gap) Initially: empl < equil. Empl unempl > natural rate R-wage > equil. R-wage downward pressure on R-waqes SAS shifts left until GDP=potential GDP As economy moves to LR Equilibrium: Employment rises Unemployment falls Real wage falls Real GDP rises

SR/LR effect of changes in AD Effect of Increase in AD on real wage, prices, real GDP unemployment and employment.