IDEAS home Printed from
MyIDEAS: Log in (now much improved!) to save this paper

The Impossibility of Rational Bubbles

Listed author(s):
  • Behzad T. Diba
  • Herschel I. Grossman

A rational bubble would involve a self-confirming belief that an asset price depends on information that includes variables or parameters that are not part of market fundamentals. The existing literature shows that, if market fundamentals are economically interesting, i.e., forward looking, any rational bubbles would be either explosive or implosive. Further arguments based on the existing literature show that utility maximizing behavior implies finite bounds on asset prices and, accordingly, precludes both explosive and implosive rational price expectations, except for the possible case of an implosion in the value of fiat money. These arguments rule out both positive and negative rational bubbles, except for the poissibility of rational inflationary bubbles.This paper extends the theoretical analysis of rational bubbles in two ways. First, it shows that, although a supply response of the current asset stock to the current asset price dampens fluctuations in market fundamentals, such a response would cause a rational bubble to explode or to implode even faster.Thus, the explosiveness or implosiveness of rational bubbles isnot an artifact of assuming that the asset stock evolves autonomously. Second, and more importantly, the present analysis considers the inception of rational bubbles and shows that, for anegative rational bubble -- such as a rational inflationary bubble -- to get started, a positive rational bubble also would have to have positive probability. Specifically, the expected initial absolute value of a potential negative rational bubble cannot exceed the expected, initial value of a potential positive rational bubble.This result dramatically expands the theoretical basis for precluding rational bubbles. Specifically, because utility maximization directly rules out rational deflationary bubbles, the inception of a rational inflationary bubbles is also precluded.

If you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.

File URL:
Download Restriction: no

Paper provided by National Bureau of Economic Research, Inc in its series NBER Working Papers with number 1615.

in new window

Date of creation: May 1985
Publication status: published as Diba, Behzad T. and Herschel I. Grossman. "On the Inception of Rational Bubbles," Quarterly Journal of Economics, Vol. 102, No. 409, August 1987.
Handle: RePEc:nbr:nberwo:1615
Note: ME EFG
Contact details of provider: Postal:
National Bureau of Economic Research, 1050 Massachusetts Avenue Cambridge, MA 02138, U.S.A.

Phone: 617-868-3900
Web page:

More information through EDIRC

References listed on IDEAS
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:

in new window

  1. Tirole, Jean, 1982. "On the Possibility of Speculation under Rational Expectations," Econometrica, Econometric Society, vol. 50(5), pages 1163-1181, September.
  2. Gray, Jo Anna, 1984. "Dynamic Instability in Rational Expectations Models: An Attempt to Clarify," International Economic Review, Department of Economics, University of Pennsylvania and Osaka University Institute of Social and Economic Research Association, vol. 25(1), pages 93-122, February.
  3. Michael Mussa, 1984. "Rational Expectations Models with a Continuum of Convergent Solutions," NBER Technical Working Papers 0041, National Bureau of Economic Research, Inc.
  4. Kingston, Geoffrey H., 1982. "The semi-log portfolio balance schedule is tenuous," Journal of Monetary Economics, Elsevier, vol. 9(3), pages 389-399.
  5. Obstfeld, Maurice & Rogoff, Kenneth, 1983. "Speculative Hyperinflations in Maximizing Models: Can We Rule Them Out?," Journal of Political Economy, University of Chicago Press, vol. 91(4), pages 675-687, August.
  6. George Evans & Seppo Honkapohja, 1986. "A Complete Characterization of ARMA Solutions to Linear Rational Expectations Models," Review of Economic Studies, Oxford University Press, vol. 53(2), pages 227-239.
  7. Flood, Robert P & Garber, Peter M, 1980. "Market Fundamentals versus Price-Level Bubbles: The First Tests," Journal of Political Economy, University of Chicago Press, vol. 88(4), pages 745-770, August.
  8. Azariadis, Costas, 1981. "Self-fulfilling prophecies," Journal of Economic Theory, Elsevier, vol. 25(3), pages 380-396, December.
Full references (including those not matched with items on IDEAS)

This item is not listed on Wikipedia, on a reading list or among the top items on IDEAS.

When requesting a correction, please mention this item's handle: RePEc:nbr:nberwo:1615. See general information about how to correct material in RePEc.

For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: ()

If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

If references are entirely missing, you can add them using this form.

If the full references list an item that is present in RePEc, but the system did not link to it, you can help with this form.

If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your profile, as there may be some citations waiting for confirmation.

Please note that corrections may take a couple of weeks to filter through the various RePEc services.

This information is provided to you by IDEAS at the Research Division of the Federal Reserve Bank of St. Louis using RePEc data.