Identify and analyse the factors that can affect the reliability of a firm’s beta

May you please assist me with answering the following question in approximately 500 – 600 words. I will also need three credible references featured in using the Harvard Referencing system.

The question is as follows;

“Identify and analyse the factors that can affect the reliability of a firm’s beta. Do you think the recent global financial crisis has had an impact on a firm’s beta, its cost of equity and its cost of capital? What are the likely implications, for both the firm and its providers of capital? “

This was the additional commentary provided by the lecturer:

“In working out your responses to the Discussion Question, you should choose examples from your own experience or find appropriate cases on the Web that you can discuss. Credit will be given for references you make to relevant examples from real companies. Please make sure that you cite and reference all your outside sources (including the textbook itself) properly, as per the Harvard Referencing System.” [Note: the Text Book in question is Hiller, D. 2nd European Edition, Corporate Finance].

Identify and analyse the factors that can affect the reliability of a firm’s beta. Do you think the recent global financial crisis has had an impact on a firm’s beta, its cost of equity and its cost of capital? What are the likely implications, for both the firm and its providers of capital?