While computing the cost of equity using the formula , rs= D1 P0+g we do not make any adjustment to express the cost of equity on an after-tax basis whereas while computing the cost of debt, a tax...

While computing the cost of equity using the formula , rs=D1

                                                                                               P0+g we do not make any adjustment to express the cost of equity on an after-tax basis whereas while computing the cost of debt, a tax adjustment is required to arrive at after-tax cost of debt. Why is this so? Explain briefly. (75-150 words)