A role for preferred stock in the financing decision of a public utility

Summary

We have shown that preferred stock has a unique role in the financing of public utility capital expenditures, particulary when returns allowed by regulatory commissions are perceived to be inadequate. From the firm's perspective there is no tax advantage for debt because the commission effectively passes the tax savings through the consumers. If allowed returns on common stock are inadequate and the firm has exhausted its perceived debt capacity, then preferred stock becomes the optimal financing instrument. The regulatory commissions compute the costs of debt and preferred stock so that companies can expect returns to cover payments on debt and preferred stock if the assets being financed are necessary and will be included in the rate base. During extremely bad years when revenues are much less than expected, the companies can delay or miss preferred stock dividends without running the risk of default. The data on new capital sources for the electric and gas utilities indicate that these companies made adjustments which are consistent with the implications of our model, but they did not follow the extreme policy of using only debt and preferred stock when market-to-book ratios for common stock were below one. Regulators have, on occasions, used capital structures for rate-making that differ from actual capital structures, and a utility might be penalized for using an extreme capital structure policy. The main emphasis of regulatory review of capital structure, however, has been on the debt component. One strategy would be to use a debt level that satisfies the regulatory commission and then adjust equity between preferred stock and common stock to maximize value for common stockholders.