The project cash flows are discounted at the weighted average cost of capital as computed by the company, and most companies use the same discount rate across divisions. The discount rate will be assumed constant for the life of the project. The WACC will be based on target weights for debt and equity. The CAPM will be used in estimating the cost
of equity capital, with the treasury-bond rate used as a proxy for the risk-free rate, beta estimates will be obtained from public sources, and the market risk premium will be in the range of six to eight percent, with six percent more likely. Asset pricing models other than the CAPM are not used in estimating the cost of capital. The cost of debt is adjusted to
allow for the effect of interest tax shields, but not by a significant minority of companies. The discount rate is reviewed regularly, at least annually, and the inputs used in the
calculation will be varied over time.