McGraw-Hill/Irwin © 2009 The McGraw-Hill Companies, All Rights Reserved Chapter 11 Spending and Output in the Short Run
11-2 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO 23- All Learning Objectives 1.Identify the key assumptions of the basic Keynesian model 2.Discuss the determination of planned investment and planned aggregate expenditure 3.Analyze how an economy reaches short-run equilibrium in the basic Keynesian model 4.Show how a change in planned aggregate expenditure can cause a change in the short-run equilibrium output
11-3 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Keynesian Model Key assumption: In the short run, firms meet demand at preset prices Firms typically set a price and meet the demand at that price in the short run Eventually, firms change prices when the marginal benefits exceed the marginal costs Basic Keynesian model developed here ignores this fact.
11-4 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Planned Aggregate Expenditure Planned aggregate expenditure is planned spending on final goods and services Four components of planned aggregate expenditure Consumption (C) by households Investment (I) is planned spending by domestic firms on new capital goods Government purchases (G) are made by federal state and local governments Net exports (NX) is exports minus imports
11-5 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Planned Investment Example Fly-by-Night Kite produces $5 million of kites per year Expected sales are $4.8 million and planned inventory increase is $0.2 million Capital expenditure of $1 million is planned Planned investment is $1.2 million If actual sales are only $4.6 million Unplanned inventory investment of $0.2 million Actual investment is $1.4 million If actual sales are $5.0 million Unplanned inventory decrease of $0.2 million Actual investment is $1.0 million
11-6 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Planned Aggregate Expenditure (PAE) Actual spending equals planned spending for Consumption Government purchases of final goods and services Net exports Adjustments between actual and planned spending are accomplished with changes in inventories The general equation for planned aggregate expenditures is PAE = C + I P + G + NX
11-7 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Consumption Expenditures Consumption (C) accounts for two-thirds of total spending Powerful determinant of planned aggregate spending Includes purchases of goods, services, and consumer durables, but not houses Rent is considered a service C depends on disposable income, (Y – T)
11-8 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Consumption,
11-9 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Consumption Function The consumption function is an equation relating planned consumption to its determinants, notably disposable income (Y – T) C = C + (mpc) (Y – T) where C is autonomous consumption spending mpc is the change in consumption for a given change in (Y – T) Autonomous consumption is spending not related to the level of disposable income A change in C shifts the consumption function
11-10 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Consumption Function C = C + (mpc) (Y – T) C captures wealth effect The effect of changes in asset prices on consumption spending C also captures the effects of interest rates on consumption Higher rates increase the cost of using credit to purchase consumer durables and other items
11-11 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO More Consumption Function C = C + (mpc) (Y – T) Marginal propensity to consume (mpc) is the increase in consumption spending when disposable income increases by $1 mpc is between 0 and 1 for the economy If households receive an extra $1 in income, they spend part (mpc) and save part (Y – T) is disposable income Output minus net taxes
11-12 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Consumption Function Disposable income (Y – T) Consumption spending (C) C C = C + (mpc) (Y – T) Δ (Y – T) Δ C C Intercept Slope = Δ C / Δ (Y – T) slope
11-13 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Planned Spending Example PAE = C + I P + G + NX C = C + mpc (Y – T) PAE = C + mpc (Y – T) + I P + G + NX Suppose that planned spending components have the following values PAE = (Y – 250) PAE = Y C = 620mpc = 0.8T = 250 I P = 220G = 330NX = 20
11-14 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Planned Spending Example C = (Y – 250) PAE = Y If Y increases by $1, C will increase by $0.80 PAE increases by 80 cents Planned aggregate expenditure has two parts Autonomous expenditure, the part of spending that is independent of output $960 in our example Induced expenditure, the part of spending that depends on output (Y) 0.8 Y in our example
11-15 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Planned Expenditure Graph Output (Y) Planned aggregate expenditure (PAE) 960 PAE = Y Slope = 0.8 4,800
11-16 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Short-Run Equilibrium Short-run equilibrium is the level of output at which planned spending is equal to output Our equilibrium condition can be written Y = PAE Using our previous example, PAE = Y Y = Y 0.2 Y = 960 Y = $4,800
11-17 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Short-Run Equilibrium Graph Output (Y) Planned aggregate expenditure (PAE) 960 PAE = Y 45 o Y = PAE 4,800 Slope = 0.8
11-18 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Output Greater than Equilibrium Suppose output reaches 5,000 Planned spending is less than total output Unplanned inventory increases Businesses slow down production Output goes down PAE Output (Y) 96 0 PAE = Y 45 o Y = PAE 4,8005,000
11-19 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Output Less than Equilibrium Suppose output is only 4,500 Planned spending is more than total output Unplanned inventory decreases Businesses speed up production Output goes up PAE Output (Y) 96 0 PAE = Y Y = PAE 4,8004,700
11-20 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Lower Equilibrium Output Y Planned aggregate expenditure (PAE) 960 E PAE = Y 45 o Y = PAE 4,800 Y* Recessionary gap PAE = Y 950 F 4,750
11-21 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO New Equilibrium Autonomous consumption, C, decreases by 10 Causes a downward shift in the planned aggregate expenditures curve The economy eventually adjusts to a new lower level of equilibrium spending an output, $4,750 Suppose that the original equilibrium level, $4,800, represented potential output, Y* A recessionary gap develops Size of the recessionary gap is 4,800 – 4,750 = $50 Entire decrease is in Consumption spending Same process applies to a decrease in I P, G, or NX –
11-22 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Japan's Recession and East Asia Japanese recession in 1990s reduced Japanese imports East Asian economies developed by promoting exports The decrease in exports to Japan decreased planned aggregate expenditures in these countries The decrease in planned spending caused the economies to contract to a new, lower level of planned spending and output Japan exported its recession to its neighbors US recessions have similar effects on our major trading partners
11-23 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Income-Expenditure Multiplier The income – expenditure multiplier shows the effect of a one-unit increase in autonomous expenditure on short-run equilibrium output Previous example Initial planned expenditure = Y New planned expenditure = Y Equilibrium changed from $4,800 to $4,750 A $10 change in autonomous expenditures caused a $50 change in output Multiplier = 5
11-24 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Stabilization Policy Stabilization policies are government actions to affect planned spending with the intention of eliminating output gaps Expansionary policies increase planned spending Contractionary policies decrease planned spending Two major stabilization tools are fiscal policy and monetary policy Fiscal policy uses changes in government spending, transfers, or taxes Monetary policy uses changes in the money supply
11-25 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Government Spending Government spending is part of planned spending Changes in government spending will directly affect planned aggregate expenditures Suppose planned spending decreases $ 10 from Y = Yto Y = Y Equilibrium Y decreases from $4,800 to $4,750 Recessionary gap is $50 Stabilization policy indicates a $10 increase in government spending will restore the economy to Y* at $4,800
11-26 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO $10 Fiscal Stimulus Output Y Planned aggregate expenditure (PAE) 960 PAE = Y 45 o Y = PAE F PAE = Y 950 4,750 E 4,800 Y*
11-27 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Japanese Spending In the 1990s Japan spent over $1 trillion on public works Highways, subways, and transportation projects Concert halls Re-laying cobblestone sidewalks Projects did not end the recession Prevented larger decrease in income Eroded consumer confidence because there was little demand Consumers reduced spending in anticipation of higher taxes in the future
11-28 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Taxes and Transfers Planned aggregate expenditures are affected by taxes and transfers The effect is indirect, channeled through the effects on disposable income Lower taxes or higher transfers increase disposable income Increases in disposable income lead to higher C
11-29 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Tax Cuts Stimulate – An Example Original planned spending PAE = Y Autonomous consumption, C, decreases by 10. Recessionary gap is $50. PAE = C (Y – T) + I P + G + NX Tax cut to close the gap must be bigger than $10 Increase disposable income to cause initial increase in spending to be $10 Taxes will have to go down by $12.5
McGraw-Hill/Irwin © 2009 The McGraw-Hill Companies, All Rights Reserved Chapter 23 Appendix A An Algebraic Solution of the Basic Keynesian Model
11-31 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO The Basic Keynesian Model PAE = C + I P + G + NX C = C + mpc (Y – T) The consumption function is defined by C, autonomous consumption mpc, the marginal propensity to consume, a number between 0 and 1 I P, G, T and NX are given – I = Iplanned investmentT = Tnet taxes G = Ggovernment purchasesNX = NXnet exports – – – –
11-32 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Find Short-Run Equilibrium Output PAE = C + mpc (Y – T) + I + G + NX PAE = C – mpc T + I + G + NX + mpc Y Equilibrium condition is PAE = Y Y = C – mpc T + I + G + NX + mpc Y Y – mpc Y = C – mpc T + I + G + NX (1 – mpc) Y = C – mpc T + I + G + NX –––––– –––– –––– –––– Y = C – mpc T + I + G + NX (1 – mpc) –––––– ––––
11-33 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Short-Run Equilibrium Example C = 620I = 220 G = 300NX = 20 T = 250mpc = 0.8 Y = 620 – 0.8 (250) (1 – 0.8) Y = 960 / 0.2 = 4,800 –– Y = C – mpc T + I + G + NX (1 – mpc) –––––– – – – –
McGraw-Hill/Irwin © 2009 The McGraw-Hill Companies, All Rights Reserved Chapter 23 Appendix B The Multiplier in the Basic Keynesian Model
11-35 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO The Income and Expenditure Multiplier Suppose autonomous spending decreases $10 and mpc is 0.8 First decrease in spending is $10 Leads to a decrease in output of $10 Second decrease in spending is $8 Third decrease is $6.40, etc. Sum of the decreases in spending … = 10 [ (0.8) 2 + (0.8) 3 …]
11-36 © The McGraw-Hill Companies, Inc., 2009 McGraw-Hill/Irwin LO Income and Expenditure Multiplier To find the sum of the series, we need a relationship when x is between 0 and 1 In our case, x = [ (0.8) 2 + (0.8) 3 …]= 10 = 10 (1 / 0.2) = 10 (5) = 50 In this case, the multiplier is 5 1 (1 – x) 1 + x + x 2 + x 3 + x 4 + … == multiplier 1 (1 – x) 1 (1 – 0.8)