The capital asset pricing model (CAPM) can be written as

E(Ri)=Rf +i[E(Rm)Rf] (3.44)

using the standard notation. The first step in using the CAPM is to estimate the stocks beta using

the market model. The market model can be written as

Rit = i + iRmt + uit (3.45)

where Rit is the excess return for security i at time t, Rmt is the excess return on a proxy for the market portfolio at time t, and ut is an iid random disturbance term. The cofficient beta in this case is also the CAPM beta for security i.

Suppose that you had estimated equation (3.45) and found that the

estimated value of beta for a stock, was 1.147. The standard error

associated with this coefficient SE() is estimated to be 0.0548.

A city analyst has told you that this security closely follows the market, but that it is no more risky, on average, than the market. This can be tested by the null hypotheses that the value of beta is one. The model is estimated over sixty-two daily observations. Test this hypothesis against a one-sided