Financial Analysts impact on Stock Volatility. A Study on the Pharmaceutical Sector
The arrival of new information helps financial markets to value assets, but it may has the side-effect of increasing their volatilities. A better knowledge of the mechanism that links relevant news and stock prices would help both private and institutional agents to improve the calibration of the risks implies in a given asset. Financial analysts play a key role in distinguishing which news are relevant for the valuation of a particular asset, and the changes in their recommendations are signals of new information in the market. This paper studies the impact those buy or sell recommendations have on returns and also on volatility instead of the traditional literature that focuses only on prices. The pharmaceutical companies in the New York Stock Exchange are especially suited for this type of analysis given the frequent discontinuities in their expected profits derived from the success or failure in the development of new drugs. Twenty stocks are daily tracked for five years along with the recommendations given by financial analysts. We have modeled stock returns by a Markov Regime Switching model as in Schaller and van Norden (1997) and found two states of low and high volatilities. We have also found strong evidence that the probability of being in the estate of high volatility increases when a Financial Analyst changes his recommendation.
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.:
- Castanias, Richard P, II, 1979. "Macroinformation and the Variability of Stock Market Prices," Journal of Finance, American Finance Association, vol. 34(2), pages 439-50, May.
- DiMasi, Joseph A. & Hansen, Ronald W. & Grabowski, Henry G., 2003. "The price of innovation: new estimates of drug development costs," Journal of Health Economics, Elsevier, vol. 22(2), pages 151-185, March.
- Turner, C.M. & Startz, R. & Nelson, C.R., 1989.
"The Markov Model Of Heteroskedasticity, Risk And Learning In The Stock Market,"
Discussion Papers in Economics at the University of Washington
89-01, Department of Economics at the University of Washington.
- Turner, C.M. & Startz, R. & Nelson, C.R., 1989. "The Markov Model Of Heteroskedasticity, Risk And Learning In The Stock Market," Working Papers 89-01, University of Washington, Department of Economics.
- Ederington, Louis H & Lee, Jae Ha, 1993. " How Markets Process Information: News Releases and Volatility," Journal of Finance, American Finance Association, vol. 48(4), pages 1161-91, September.
- Danzon, Patricia M & Chao, Li-Wei, 2000. "Does Regulation Drive out Competition in Pharmaceutical Markets?," Journal of Law and Economics, University of Chicago Press, vol. 43(2), pages 311-57, October.
- Womack, Kent L, 1996. " Do Brokerage Analysts' Recommendations Have Investment Value?," Journal of Finance, American Finance Association, vol. 51(1), pages 137-67, March.
- DiMasi, Joseph A. & Hansen, Ronald W. & Grabowski, Henry G. & Lasagna, Louis, 1991. "Cost of innovation in the pharmaceutical industry," Journal of Health Economics, Elsevier, vol. 10(2), pages 107-142, July.
- Hamilton, James D., 1990. "Analysis of time series subject to changes in regime," Journal of Econometrics, Elsevier, vol. 45(1-2), pages 39-70.
- Douglas K. Pearce & V. Vance Roley, 1984.
"Stock Prices and Economic News,"
NBER Working Papers
1296, National Bureau of Economic Research, Inc.
- Hamilton, James D, 1989. "A New Approach to the Economic Analysis of Nonstationary Time Series and the Business Cycle," Econometrica, Econometric Society, vol. 57(2), pages 357-84, March.
- Clark, Peter K, 1973. "A Subordinated Stochastic Process Model with Finite Variance for Speculative Prices," Econometrica, Econometric Society, vol. 41(1), pages 135-55, January.
- Christopher M. Turner & Richard Startz & Charles R. Nelson, 1989.
"A Markov Model of Heteroskedasticity, Risk, and Learning in the Stock Market,"
NBER Working Papers
2818, National Bureau of Economic Research, Inc.
- Turner, Christopher M. & Startz, Richard & Nelson, Charles R., 1989. "A Markov model of heteroskedasticity, risk, and learning in the stock market," Journal of Financial Economics, Elsevier, vol. 25(1), pages 3-22, November.
- Engle, Robert F, 1982. "Autoregressive Conditional Heteroscedasticity with Estimates of the Variance of United Kingdom Inflation," Econometrica, Econometric Society, vol. 50(4), pages 987-1007, July.
- Hamilton, James D. & Susmel, Raul, 1994.
"Autoregressive conditional heteroskedasticity and changes in regime,"
Journal of Econometrics,
Elsevier, vol. 64(1-2), pages 307-333.
- Tom Doan, . "RATS programs to estimate Hamilton-Susmel Markov Switching ARCH model," Statistical Software Components RTZ00083, Boston College Department of Economics.
- Hansen, Bruce E, 1992. "The Likelihood Ratio Test under Nonstandard Conditions: Testing the Markov Switching Model of GNP," Journal of Applied Econometrics, John Wiley & Sons, Ltd., vol. 7(S), pages S61-82, Suppl. De.
- Benoit Mandelbrot, 1963. "The Variation of Certain Speculative Prices," The Journal of Business, University of Chicago Press, vol. 36, pages 394.
When requesting a correction, please mention this item's handle: RePEc:fda:fdaddt:2008-19. 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: (Carmen Arias)
If references are entirely missing, you can add them using this form.