Question

An increase in a firm's tax rate will__________ if the firm has debt capital in its capital structure:

a. increase both the cost of preferred stock and debt.
b. decrease the cost of preferred stock.
c. increase the firm's WACC.
d. decrease the firm's WACC.

Answer 1

d. decrease the firm's WACC.

Step-by-step explanation:

As per WACC formula

WACC = ( Weight of Common Equity x Cost of Common Equity ) + ( Weight of Common Debt x Cost of Common Debt x ( 1 - Tax rate ) ) + ( Weight of Preferred Equity x Cost of Preferred Equity )

By assuming the values to prove the answer

Weights

Common equity = 55%

Preferred Equity = 15%

Debt = 30%

Costs

Common equity = 15%

Preferred Equity = 8%

Debt = 12%

Tax rate is 15%

Placing values in the formula

WACC = ( 55% x 15% ) + ( 30% x 12% x ( 1 - 15% ) ) + ( 15% x 8% )

WACC = 8.25% + 3.06% + 1.2% = 12.51%

Keeping others values constant, Now increase the Tax rate to 25% and placing vlaues in the formula

WACC = ( 55% x 15% ) + ( 30% x 12% x ( 1 - 25% ) ) + ( 15% x 8% )

WACC = 8.25% + 2.7 + 1.2% = 12.15%

Hence the WACC is decreased from 12.51% to 12.15% when the tax rate is increased from 15% to 25% keeping other values constant.