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Chapter 22. Understanding Business Cycle Fluctuations. Understanding Business Cycle Fluctuations: The Big Questions. Why do aggregate demand curve and aggregate supply curves shift? How do central bankers achieve their stabilization objectives?. Inflation and Business Cycles.
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Chapter 22 Understanding Business Cycle Fluctuations
Understanding Business Cycle Fluctuations: The Big Questions • Why do aggregate demand curve and aggregate supply curves shift? • How do central bankers achieve their stabilization objectives?
Understanding Business Cycle Fluctuations: Roadmap • Sources of Fluctuations • Using the Aggregate Demand-Aggregate Supply Framework
Sources of Fluctuations:Preliminaries • Long-run equilibrium • Y = YP output = potential • = T inflation = target • = e inflation = expected • Shocks • Supply shock: affects cots • Demand shock: affects expenditure
Sources of Fluctuations • Shifts in Aggregate Demand • Change in the inflation target (T) • Change in Government Purchases • Shifts in Short-Run Aggregate Supply • Changes in costs of production
Decline in Inflation Target:Monetary Policy Reaction Curve When T , MPRC shifts to the left.
Decline in Inflation Target:Short-Run Equilibrium T AD shifts left Economy 12
Decline in Inflation Target:Adjustment At point 2, Y<YP SRAS shifts right Until economy reaches point 3, the new long-run equilibrium
Decline in Inflation Target:Summary • Output falls and inflation falls. • With Y<YP, output starts to rise and inflation continues to fall. • At the new equilibrium, Y=YP and inflation equals the new target
Increase in Government PurchasesShort-Run Equilibrium G Shifts AD to the right Economy 12
Increase in Government PurchasesAdjustment At point 2, Y>YP SRAS shifts left Until economy reaches long-run equilibrium at point 3
Increase in Government PurchasesSummary • Output initially rises and inflation rises • With Y>YP, output and inflation fall • The economy returns to its initial equilibrium. An increase in G causes Y and to increase temporarily.
Shifts in Short-Run Aggregate Supply Increase in production cost changes shift SRAS left Economy 1 2
Recession: • Decline in activity, not just a dip in growth • Exact length is ambiguous. • Determination involves judgment
A Shift in Aggregate Demand Drop in consumer or business confidence: AD0 AD1 Economy 12 Stabilization requires shifting AD back towhere it started
A Shift in Aggregate Demand:Policy Response • Drop in consumer or business confidence lowers r* • Policymakers shift MPRC right, lowering the interest rate at every level of inflation
A Shift in Aggregate Demand:Stabilization To stabilize the economy following a drop in confidence, policymakers shift AD back to where it started
Stabilization improves welfare • Individuals strive to stabilize consumption • When income falls temporarily you can • Draw on savings (emergency funds) • Borrow
Fiscal Policy • Two types • Automatic stabilizers • Discretionary policy • Discretionary increase in G • Drives up aggregate expenditure • Shifts dynamic aggregate demand right • Elicits a monetary policy response: higher interest rates at every level of inflation
Positive Supply Shock Fall in Production Costs:Shifts SRAS Right Economy 12
Positive Supply Shock:Policy Options 1. Tunchanged 2. Lower T
Positive Supply Shock:Policy Option 1 Tunchanged At point 2, Y>YP SRAS shifts left until Y=YP at point 1
Positive Supply Shock:Policy Option 2 Policymakers take advantage and lower T Shifts MPRC left
Positive Supply Shock:Policy Option 2 New, lower T AD shifts left Economy 23
The Great Moderation Growth is much less volatile after 1984 than before.
The Great Moderation:Candidate Explanations • LuckBut there were lots of shocks in the 1990s • Improved technology, especially for inventory managementBut the biggest inventory problems are in the high-technology sector • Better monetary policy
Increase in Potential Output • Source:Technological Improvement • How to think about it:An Increase in Trend Growth • Using the model:Shifts both LRAS and SRAS
Increase in Potential Output:Shifts in Aggregate Supply An increase in YPshifts SRAS rightshifts LRAS right But SRAS still crosses LRAS where = e
Increase in Potential Output:Short-Run Equilibrium Following YP increase:Economy 12where AD crosses new SRAS1
Increase in Potential Output:Long-Run • In the short-run output and inflation fall • In the long-run the economy goes to the new, higher YP • Policymakers have two options: • Tunchanged • T lower (opportunistic disinflation)
Increase in Potential Output:Unchanged Inflation Target With Tunchanged: Policymakers shift AD right, economy moves to the new level of potential output and the original Tat point 3.
Increase in Potential Output:Lower Inflation Target With a new, lower T:Policymakers allow the economy to move to point 4
Globalization and Inflation • What is Globalization? • Globalization is about trade • Improved trade is the same as a technological advance • This is the same as an increase in potential output
Globalization and Inflation • How big is the effect on inflation? • 8% of household purchases are imports • Domestic content of imports = 1/3 • Imported goods prices account for 6% of household spending
Distinguishing a Recessionary Gap from a Fall in Potential Output When output falls is it • A recessionary gap • A fall in potential output How can you tell the difference?
Recessionary Output Gap Recessionary output gap caused by supply shock Policymakers focus on returning inflation to target, raise the interest rate along an unchanged MPRC
Fall in Potential Output Fall in potential output requires policymakers to shift MPRC. This shifts AD so that inflation returns to target at point 3.
You can measure GDP by either counting production or income. They should be the same, but they are not. The difference is called the “Statistical discrepancy” and it can be very large.
The Volatility Tradeoff • Can Policymakers Stabilize Output and Inflation Simultaneously?
The Volatility Tradeoff • Demand Shocks can be neutralized • Supply Shocks create a tradeoff
The Volatility Tradeoff • Can Policymakers Stabilize Output and Inflation Simultaneously? NO! • Keeping near T means Y volatile • Keeping Y near YP means volatile
Chapter 22 End of Chapter