For a more extensive discussion , see N. Gregory Mankiw , Macroeconomics , Fourth Edition ( New York , N.Y. : Worth Publishers , 2000 ) , pp. 90-97 ; or Olivier Blanchard , Macroeconomics , Second Edition ( Upper Saddle River , N.J. : Prentice Hall , 2000 ) , pp. 214-220 .
There is a very brief discussion in Macroeconomics , Fourth Edition .