Regulation and the Term of the Risk Free Rate: Implications of Corporate Debt Available to Purchase

This paper examines the appropriate term of the risk free rate to be used by a regulator in price control situations, most particularly in the presence of corporate debt. If the regulator seeks to ensure that the present value of the future cash flows to equity holders equals their initial investment then the only choice of term for the risk free rate that can achieve this is that matching the regulatory cycle, but it also requires that the firm match its debt duration to the regulatory cycle. Failure of the firm to do so leads to cash flows to equity holders whose net present value will tend to be negative, and will also inflict interest rate risk upon equity holders. This provides the firm with strong incentives to match its debt duration to the regulatory cycle.