Modigliani and Miller Proposition II states that: the optimal capital structure occurs when the marginal cost of distress equals the marginal benefit of interest tax shields the cost of cost of levered equity is equal to the cost of unlevered equity, in the absence of taxes, since the value of the levered firm equals the value of the unlevered firm. the capital structure if the firm is irrelevant, regardless of the corporate tax rate. the cost of levered equity is equal to the cost of unlevered equity plus a premium that is proportional to the (market value) debt-to-equity ratio