Classical versus keynes


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Classical versus keynes

  1. 1. Keynesian Economics: Revolution and Counterrevolution• John Maynard Keynes (1883-1946) – Son of John Neville Keynes author of Scope and Method of Political Economy (1891) – Studied Math at Cambridge, resulted in Treatise on Probability (1921) – Attracted into economics by Marshall – Brief period at the India Office – Returned to Cambridge at Kings College – Worked mainly on monetary policy – Involved in post WWI peace conference and critical of the settlement
  2. 2. J. M. Keynes– The Economic Consequences of the Peace (1919)– Tract on Monetary Reform (1923)– Treatise on Money (1930)– Break with neoclassical theory– The General Theory of Employment, Interest and Money (1936)– Focus on employment levels and the possibility of an unemployment equilibrium– General Theory—it includes full employment equilibrium as a special case– Keynes a member of the Bloomsbury Group of artists, writers, and intellectuals
  3. 3. Keynes’ Critique of the “Classical” Postulates: I• The Classical Labour Market – In classical and neoclassical economics the demand and supply of labour determines the real wage rate – Cannot be involuntary unemployment in equilibriumW/P S w w’ D D’ N n’ n
  4. 4. Labour Markets• The Keynesian Labour Market – Wage bargaining is about money wages not real wages – Wage bargaining cannot determine the real wage as price level changes may occur – Workers react differently to a cut in real wages caused by price level increases than to cuts in money wage rates – Workers resist money wage cuts – Importance of relative position, no union will want to accept wage cuts in case others do not
  5. 5. Keynesian Labour MarketMoney wages Sw D D’ N n’ n Involuntary employment exists because of downwardly inflexible money wage rates. ISSUE: Is this assumption critical to the Keynesian analysis?
  6. 6. Keynes’ Critique of theClassical Postulates: II• The Classical theory of the interest rate, savings and investment – The real interest rate is determined by savings and investment – The real interest rate co-ordinates saving and investment – What is saved will be spent in the form of investment expenditure
  7. 7. Classical Interest Rate TheoryReal i rate S S’ii’ I S&I If the desire to save rises, interest rates fall and investment increases.
  8. 8. Keynesian Theory of Interest, Savings and Investment• The interest rate is a monetary phenomenon determined in the money market• Savings primarily a function of income and not very responsive to the interest rate• Investment determined by the interest rate but, more importantly, by the state of business expectations• The amount people wish to save at full employment levels of income may not equal the level of investment planned by businesses
  9. 9. Keynesian Theory of Interest, Savings and InvestmentMoney i rate S at FE i I I’i is determined in the money marketBoth S and I are interest inelasticI can shift in due to adverse expectations soThat at i FE levels of S > I
  10. 10. Keynesian Critique of Classical Postulates: III• Classical Theory of the Demand for Money – Demand for money for transactions purposes – M = PTk• Keynesian Theory of the Demand For Money – Demand for money for transactions and as an asset – At certain times people may rather hold their assets as money than as stocks or bonds
  11. 11. Keynes and Say’s Law• Keynes’ critique of the classical savings/investment theory and the classical demand for money theory constitute a rejection of Say’s law• At full employment all income is not necessarily spent as desired saving may exceed desired investment or people may wish to increase their money holdings• If this happens there is underconsumption in the sense that FE Agg S > Agg D• QUESTION: are there adjustment processes that will lead back to FE?
  12. 12. The Keynesian Model• Short run analysis, organization, technology and capital stock taken as given• Aggregation of Marshallian concepts• Aggregate supply and aggregate supply price• Agg supply drawn as a function of employment• Agg supply price is the amount of income factors would have to earn to maintain that level of employment
  13. 13. Aggregate SupplyProceeds or income Z NZ function rises at an increasing rate due todiminishing returns—increasing marginalsupply priceZ function in money terms and so assumesa given price level
  14. 14. Aggregate Demand• Aggregate demand or aggregate demand price• Agg D drawn as a function of employment• As employment rises so does income and expenditure but expenditure rises by less than income• The equilibrium level of employment is where Agg D = Agg S and this may or may not be full employment
  15. 15. Equilibrium Employment LevelIncome and expenditure Zy* D=C+I n* NTo proceed Keynes examines the componentsof D (C and I) more closely and as a functionof income rather than of employment
  16. 16. Consumption and Savings• Keynes lists numerous factors both subjective and objective that might affect the “propensity to consume out of income”• Keynes argues that consumption primarily a function of real income• Propensity to consume and the marginal propensity to consume• The consumption function— consumption as a function of income• Keynes thought MPC would tend to decline with income but usually drawn as constant
  17. 17. Consumption and Savings• APC = C/Y• MPC = ΔC/ΔY• C = a + bY where b =MPCC 450 or C = Y C = a+ bY Slope = b a y yFE Y
  18. 18. Consumption and Savings• What is not consumed out of income is saved• Y=C+S• APC + APS = 1• MPC + MPS = 1S S Y y yFE -a
  19. 19. Consumption and Savings• Important to note that Keynes thought of the consumption function as very stable• Changes in consumption and savings due to movements along the consumption function (due to changes in income) not due to shifts in the consumption function (which would be caused by changes in the propensity to consume out of income)
  20. 20. Investment Expenditure• Investment depends on interest rate and the expected future earnings from the investment• These are long term expectations• Lack of a rational basis for expectations of earnings a long time in the future• State of expectations has a conventional basis only and can change quite quickly
  21. 21. Investment Expenditurei Optimistic Pessimistic MEI I MEI curve is very interest inelastic and is unstable—tends to shift with state of expectations
  22. 22. Equilibrium IncomeFor an equilibrium Agg D = Agg SY=C+I 450Agg D C + I = Agg D S C C y* FE YAt y* Agg D = Agg S and S = IHowever y* need not be FEIf FE > y* then Aggs > Agg D and S > IFirms will find inventories accumulating and willreduce employment and income until S = I
  23. 23. The Multiplier• R. F. Kahn (1931) – Changes in autonomous expenditures, such as investment, will have a multiplied impact on income – Initial expenditure change will affect incomes by that amount – Income change will then affect the consumption expenditures of those affected (by change in income x MPC) – This will affect other peoples’ incomes and will alter their expenditures in the same way – Ultimate effect will be the change in autonomous expenditure times the multiplier where M = 1/(1 – MPC)
  24. 24. Implications of the Analysis so Far• Equilibrium is where Agg D = Agg S• The consumption function is stable but the investment function is not• Investment prone to shifts due to changes in business expectations• Shifts in I have multiplied effect on income• Economic instability due to real not monetary factors• To complete the model need to look at interest rate determination in the monetary sector
  25. 25. Money and Interest Rates• Savings depend on income but there is still a choice of how to hold ones savings• Desire to hold bonds vs money• Liquidity preference – Transactions demand for money – Precautionary demand for money – Speculative demand for money• Speculative demand is an asset demand• Will hold money if bond prices expected to fall and bonds if bond prices expected to rise
  26. 26. Money and Interest Rates• Will expect bond prices to fall if interest rates are expected to rise and vice versa• Different people may have different expectations but when interest rates are at very low levels most people will expect a rise rather than another fall and will want to hold money rather than bonds
  27. 27. Money and Interest Rates• Speculative demand for money and the liquidity trap i Ms i LP M Spec Demand Trans and Precautionary Demand
  28. 28. The Complete Keynesian Model ii Msi LP MEI M I I C+I Agg D C I 450 Y y*
  29. 29. Adjustment Processes to Full Employment?• If y* is at less than FE does anything happen to drive the economy back to FE?• If wages and prices are inflexible downwards then nothing happens• If wages and prices are flexible downward then the price level will fall• This will increase the real money supply, reduce i rates, increase investment and increase Agg D and income• Keynes Effect
  30. 30. Limitations to the Keynes Effect• The Keynes effect will likely not be powerful enough to move the economy back to full employment• Liquidity trap—increase in real money supply may simply be absorbed into speculative balances• Interest inelasticity of investment• Deflation would cause adverse shifts in business expectations
  31. 31. Policy Implications• Prolonged recessions due to insufficient Agg D• Low and stable interest rates to encourage private investment• “Social control” over investment expenditures• “Keynesian” policy after WWII became use of fiscal policy (government expenditure and tax policy) to maintain low levels of unemployment• Abba Lerner, Joan Robinson and others, “Functional Finance” to maintain very low unemployment levels
  32. 32. Hicks/Hansen Model• Problem with Keynesian model is that is goes sequentially from interest rate determination to income determination• Level of income will also affect demand for money• Need simultaneous determination of equilibrium levels of i and y• Aggregated general equilibrium approach—LM and IS curves
  33. 33. LM and IS Curves• IS curves shows all the combinations of i and y that will give I = S• As i falls, I rises, so to maintain I = S income will have to be higher• LM curve shows all combinations of i and y that will give Md = Ms (for a given Ms)• As i falls, speculative demand for money rises, so to maintain Md = Ms, income will have to be lower to reduce transactions demand
  34. 34. LM and IS Curves• LM and IS curvesi LMi IS Y y
  35. 35. Patinkin, Pigou, and the Real Balance Effect• Critique of Keynes’ view that there could be an unemployment equilibrium• Based on the idea that with flexible wages and prices unemployment will lead to falling prices and an increase in the value of money balances• Eventually people will cease trying to increase their money holdings and will increase consumption• Does not rely on interest rate declines or investment expenditure
  36. 36. Real Balance Effecti LM IS’ IS Y y* FEFall price level at y* leads to increase in theReal value of peoples’ money holdings,Eventually shifting the IS curve rightwards
  37. 37. Patinkin• Patinkin’s argument was similar but explicitly included the labour market• With y < FE both wages and prices fall• As they fall in proportion, real wages remain unchanged and involuntary unemployment exists (does not deny the reality of involuntary unemployment even with flexible money wages)• Wage and price declines will eventually shift IS curve rightward via real balance effect• But long run and slow process
  38. 38. Post WarKeynesian/Neoclassical Synthesis• Exemplified by Paul Samuelson• Neoclassical microeconomics• Keynesian macroeconomics treated as a short run model relying on inflexible wages and prices• Keynesian model a special case but the relevant special case for policy purposes
  39. 39. Inflation and the Phillips Curve• The standard Keynesian models did not incorporate the price level• Low unemployment policy began to cause inflation• A. W. Phillips (1958) empirical study on the relationship between unemployment and % change in wage rates• Phillips curve led to notion of an unemployment/inflation trade off
  40. 40. Phillips CurveRate of change in wages0 5% unemployment Idea of “buying” lower unemployment With higher rate of inflation
  41. 41. Phillips Curves and Expectations• Difficulty with the trade off idea is that inflation seemed to get worse• Notion of inflationary expectations being built into the next round of wage bargains• Keeping unemployment below the “natural rate” (consistent with zero inflation) results in the long run in accelerating inflation• Long run Phillips curve is vertical at the natural rate• Rational expectations
  42. 42. The Policy Debate• Keynesians who favored low unemployment targets argued for further government intervention in the form of wage and price controls• Many countries experimented with wage and price guideposts or controls in the 1960s and 70s• The policy alternative came from the Monetarists• Milton Friedman and Chicago
  43. 43. Friedman and Monetarism• Friedman’s critique of Keynesian economics had several dimensions• Consumption expenditure responds to changes in permanent income not temporary changes in income• Monetary factors have greater significance than Keynes or the Keynesians allowed• Studies in the Quantity Theory of Money 1956
  44. 44. Friedman and Monetarism• Restatement of the quantity theory in the framework of consumer choice theory• Demand for money will depend on total wealth, the prices and returns on various types of assets, and consumer preferences• Demand for real money balances is stable• Increases in money supply will have only a temporary effect on i rates and expenditure• Longer run effect on the price level
  45. 45. Friedman and Monetarism• Monetary authorities cannot peg interest rates• Monetary rule—keep the rate of growth of the money supply equal to the long run rate of growth• This will generate price stability• Monetarist policies introduced did eventually squeeze out inflation but at the cost of a significant recession and high interest rates in the short run
  46. 46. Keynesianism, Monetarism and Econometrics• Keynes himself was skeptical about econometric methods• But Keynesian models could be empirically estimated• National income data etc• Cowles Commission, and structural Keynesian Models• Friedman’s critique—simple models and predictive ability• Cowles versus Chicago
  47. 47. The Present State• “Keynesian” models—short run models with various types of market imperfections• Long run models of a more “classical” character—rational expectations, policy neutrality• More emphasis on long run issues of government debt, growth, intergenerational issues• Central banks and inflation targets