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

El peligro de utilizar betas calculadas

Listed author(s):
  • Fernandez, Pablo


    (IESE Business School)

  • Carabias, Jose M.

    (IESE Business School)

En este artículo se muestra que es un error enorme utilizar las betas calculadas con datos históricos para calcular la rentabilidad exigida a las acciones o para medir la gestión de una cartera de valores. Por 7 razones: porque cambian mucho de un día para otro; porque dependen de qué índice bursátil se tome como referencia. porque dependen mucho de qué periodo histórico (5 años, 3 años,…) y de qué rentabilidades (mensuales, anuales,…) se utilicen para su cálculo; porque con mucha frecuencia no sabemos si la beta de una empresa es superior o inferior a la beta de otra empresa; porque tienen muy poca relación con la rentabilidad posterior de las acciones; y porque la correlación (y la R2) de las regresiones que se utilizan para su cálculo son muy pequeñas. Debido a estas 7 razones podemos afirmar que o bien la beta calculada con datos históricos no es una buena aproximación al riesgo de la empresa, o bien el CAPM no funciona (hay más factores que afectan a su rentabilidad exigida, además de la covarianza de la rentabilidad de una empresa con la rentabilidad del mercado, la tasa sin riesgo y la prima de riesgo del mercado), o bien, ambas cosas a la vez.

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 IESE Business School in its series IESE Research Papers with number D/685.

in new window

Length: 30 pages
Date of creation: 17 Mar 2007
Handle: RePEc:ebg:iesewp:d-0685
Contact details of provider: Postal:
IESE Business School, Av Pearson 21, 08034 Barcelona, SPAIN

Web page:

More information through EDIRC

No references listed on IDEAS
You can help add them by filling out this form.

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:ebg:iesewp:d-0685. 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: (Noelia Romero)

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.