Why do you think it is important to use the market values of debt and equity, rather than book values, to calculate a firm’s WACC? Assuming that there are no corporate income taxes, how can the costs...

Why do you think it is important to use the market values of debt and equity, rather than book values, to calculate a firm’s WACC?

Assuming that there are no corporate income taxes, how can the costs of preferred stock and debt be estimated without finding a preferred stock and a bond beta?