Theories of Expectations Including Rational Expectations and Their Uses in Different Versions of the Philips Curve

  • Pradip MaitiEmail author


Expectations are used in almost every branch of economics. And alternative theories of expectations have been developed, including the theory of rational expectations (RE) introduced by Robert Lucas (Jr.). The use of RE in macroeconomic models has changed radically many well-developed earlier results and policy prescriptions. The purpose of the present paper is twofold—first, to discuss the various theories of expectations, and secondly, to show how the Phillips curve in macroeconomics dealing with the celebrated trade-off between inflation and unemployment—yield different results, if alternative expectations mechanisms are used. We thus discuss different versions of the Phillips curve—first, its initial version due to Phillips, showing the existence of a permanent trade-off between inflation and unemployment, next the Friedman–Phelps version using static expectations and showing the existence of only temporary, but no permanent trade-off, and finally, the new classical version with rational expectations showing the absence of any trade-off even temporarily. We add that no new result has been proved here; rather, our objective is mainly to help the students to understand these topics clearly—students who might have felt that the discussion of these topics in the standard textbooks is not always up to expectation.


Expectations—Static Adaptive (AE) and Rational Expectations (RE) Cobweb model Systematic error Serially correlated Mathematical expectation Mark-up pricing Trade-off Phillips curve (PC) Natural level of output Expectations-augmented Phillips Curve White noise New classical New Keynesian Phillips curve Lucas critique NAIRU 


  1. Blanchard, O. J. (1990). Why does money affect output? A Survey. In B. M. Friedman & F. H. Hahn (Ed.), Handbook of monetary economics (Vol. II, Chap. 15). Elsevier Science Publishers B. V.Google Scholar
  2. Blanchard, O. J., & Fisher, S. (1989). Lectures on macroeconomics. Cambridge: Massachusetts Institute of Technology.Google Scholar
  3. Cagan, P. (1956). The monetary dynamics of hyperinflation. In M. Friedman (Ed.), Studies in the quantitative theory of money. University of Chicago Press.Google Scholar
  4. Carter, M., & Maddock, R. (1984). Rational expectations: Macroecnomics for the 1980s?. London: Macmilan.CrossRefGoogle Scholar
  5. Chakraborty, S. R. (2002). Microeconomics. New Delhi: Allied Publishers Pvt. Ltd.Google Scholar
  6. Friedman, M. (1968, March). The role of monetary policy. American Economic Review, 58, 1–17.Google Scholar
  7. Fuhrer, J., Kodrzycki, Y. K., Little, J. S., & Olivei, G. P. (2009). The Phillips curve in historical context. In J. Fuhrer, Y. K. Kodrzycki, J. S. Little, & G. P. Olivei (Eds.), Understanding inflation and the implications for monetary policy: A Phillips curve retrospective. Cambridge: The MIT Press.CrossRefGoogle Scholar
  8. Gali, J. (2008). Monetary policy, inflation, and the business cycle: An introduction to the new Keynesian framework. Princeton and Oxford: Princeton University Press.Google Scholar
  9. Keynes, J. M. (1936). The general theory of employment, interest and money. The Macmillan Press Limited.Google Scholar
  10. Keynes, J. M. (1939). Relative movements in real wages and output. Economic Journal, 49, 34–51.CrossRefGoogle Scholar
  11. Lipsey, R. G. (1960, February). The relation between unemployment and the rate of change of money wage rates in the United Kingdom, 1862–1957: A further analysis. Economica, New Series 37(105), 1–31.CrossRefGoogle Scholar
  12. Lucas, R. E. (1972). Expectations and the neutrality of money. Journal of Economic Theory, 4, 103–124.CrossRefGoogle Scholar
  13. Lucas, R. E. (1973). Some international evidence on the output-inflation trade-offs. American Economic Review, 63, 326–334.Google Scholar
  14. Lucas, R. E. (1976). Econometric policy analysis: A critique. Carnegie-Rochester Conference on Public Policy, 1, 19–46. 19. (Available in the book by Lucas, R. E. (1981). Studies in business cycles theory. Cambridge, MA: MIT Press).Google Scholar
  15. Lucas, R. E., & Sargent, T. J. (Eds.). (1981). Rational expectations and econometric practice. London: George Allen and Unwin.Google Scholar
  16. Mankiw, N. G., & Romer, D. (Eds.). (1991). New Keynesian economics. In Imperfect competition and sticky prices (Vol. 1). Cambridge: The MIT Press.Google Scholar
  17. Metzler, L. (1941, August). The nature and stability of inventory cycle. Review of Economics and Statistics, 23, 113–129.CrossRefGoogle Scholar
  18. Muth, J. F. (1961). Rational expectations and theory of price movement. Econometrica, 29, 315–335.CrossRefGoogle Scholar
  19. Phelps, E. S. (1967). Phillips Curves, expectations of inflation and optimal unemployment over time. Economica, 34, 254–281.CrossRefGoogle Scholar
  20. Phillips, A. W. (1958, November). The Relation between unemployment and the rate of change of money wage rates in the United Kingdom, 1861–1957. Economica, 25, 283–299.Google Scholar
  21. Tobin, J. (1972). The wage price mechanism: Overview of the conference. In O. Eckstein (Ed.), The econometrics of price determination (pp. 5–15). Board of Governors of the Federal Reserve System.Google Scholar
  22. Whelan, K. (2005). Topic 7: The New-Keynesian Phillips curve.

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© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  1. 1.(Former Professor) Indian statistical InstituteKolkataIndia

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