Which equation represents the interest tax shield?

The correct representation of the interest tax shield is given by the equation that equals the corporate tax rate multiplied by interest payments. This equation illustrates how the interest expense on debt reduces a company's taxable income, effectively lowering the total tax liability.

The interest tax shield arises from the fact that interest payments are tax-deductible. When a company incurs debt and pays interest on that debt, it can subtract those interest expenses from its income before calculating taxes. This means that the higher the interest payments, the larger the tax shield provided, assuming the corporate tax rate remains constant. Thus, by multiplying the corporate tax rate by the total interest payments, you arrive at the amount of tax savings, which is a fundamental concept in corporate finance related to optimizing capital structure and tax efficiency.

Understanding this relationship is crucial for managers in evaluating financing options, as it highlights the benefit of debt financing compared to equity financing, which does not provide a similar tax shield on dividends.