Economic Efficiency And “Prudence” Analysis Of Power Plant Investment

The various deregulation proposals for the electric utility sector rely on market forces to provide incentives. Even within the traditional regulatory framework, using market behavior instead of regulators' views as a criterion for regulatory decisions is part of the spectrum of deregulation proposals. This paper proposes such an implicit deregulation of rate base decisions. It presents an efficiency standard with which public utility commissions (PUCs) should conduct their “prudence” analyses of power plant construction costs. Prudence reviews, as typically conducted by PUCs, are likely to change the risk structure in regulated sectors so as to make both ratepayers and shareholders worse off. Moreover, the correct perspective for such analyses is ex ante rather than ex post. This means that the expected costs and benefits of alternative actions are the correct parameters for evaluating prudence, and that the interests of ratepayers are consistent only with this economic efficiency approach to prudence analysis. Average industry behavior is the correct standard for implementing the efficient prudence criterion. This paper describes an alternative procedure that PUCs can use to conduct prudence reviews correctly.