The Existence of Informationally Efficient Markets When Individuals Are Rational
A rational-expectations equilibrium with positive demand for financial information does exist under fully revealing asset price-contrary to a wide-held conjecture. Generalizing the common additive signal-return model with CARA utility to the family of distributions with moment generating functions, this paper shows that individual investors en- dowed with an average portfolio demand information in equilibrium if they can adjust portfolio size. More information diminishes the ex- pected excess return of a risky asset so that investors who only have a choice of portfolio composition or whose asset endowments strongly differ from the average portfolio are worse off. Under fully revealing price, information market equilibria both with and without informa- tion acquisition are Pareto efficient.
|Date of creation:||01 Aug 2004|
|Date of revision:|
|Contact details of provider:|| Postal: 9500 Gilman Drive, La Jolla, CA 92093-0508|
Phone: (858) 534-3383
Fax: (858) 534-7040
Web page: http://www.escholarship.org/repec/ucsdecon/
More information through EDIRC
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.:
- Routledge, Bryan R, 1999. "Adaptive Learning in Financial Markets," Review of Financial Studies, Society for Financial Studies, vol. 12(5), pages 1165-1202.
- Gadi Barlevy & Pietro Veronesi, .
"Information Acquisition in Financial Markets,"
CRSP working papers
484, Center for Research in Security Prices, Graduate School of Business, University of Chicago.
- David Romer, 1992.
"Rational Asset Price Movements Without News,"
NBER Working Papers
4121, National Bureau of Economic Research, Inc.
- Morris, Stephen & Shin, Hyun Song, 1997.
"Unique Equilibrium in a Model of Self-fulfilling Currency Attacks,"
CEPR Discussion Papers
1687, C.E.P.R. Discussion Papers.
- Morris, Stephen & Shin, Hyun Song, 1998. "Unique Equilibrium in a Model of Self-Fulfilling Currency Attacks," American Economic Review, American Economic Association, vol. 88(3), pages 587-97, June.
- Morris, S & Song Shin, H, 1996. "Unique Equilibrium in a Model of Self-Fulfilling Currency Attacks," Economics Papers 126, Economics Group, Nuffield College, University of Oxford.
- Grossman, Sanford J & Stiglitz, Joseph E, 1976. "Information and Competitive Price Systems," American Economic Review, American Economic Association, vol. 66(2), pages 246-53, May.
- Bhattacharya, Sudipto & Pfleiderer, Paul, 1985. "Delegated portfolio management," Journal of Economic Theory, Elsevier, vol. 36(1), pages 1-25, June.
- Admati, Anat R., 1991. "The informational role of prices : A review essay," Journal of Monetary Economics, Elsevier, vol. 28(2), pages 347-361, October.
- Radner, Roy, 1979. "Rational Expectations Equilibrium: Generic Existence and the Information Revealed by Prices," Econometrica, Econometric Society, vol. 47(3), pages 655-78, May.
- Jackson, Matthew O, 1991. "Equilibrium, Price Formation, and the Value of Private Information," Review of Financial Studies, Society for Financial Studies, vol. 4(1), pages 1-16.
- Alessandro Citanna & Antonio Villanacci, 2000. "Existence and regularity of partially revealing rational expectations equilibrium in finite economies," Post-Print hal-00463207, HAL.
- Citanna, Alessandro & Villanacci, Antonio, 2000. "Existence and regularity of partially revealing rational expectations equilibrium in finite economies," Journal of Mathematical Economics, Elsevier, vol. 34(1), pages 1-26, August.
- Jordan, J S, 1983. "On the Efficient Markets Hypothesis," Econometrica, Econometric Society, vol. 51(5), pages 1325-43, September.
When requesting a correction, please mention this item's handle: RePEc:cdl:ucsdec:qt5tf543q2. 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: (Lisa Schiff)
If references are entirely missing, you can add them using this form.