A Note on Measuring the Productivity Offset for Regulatory Purposes

Calculation of the productivity offset or the X-factor used in setting price caps has a fundamental flaw when it is based on conventional growth accounting total factor productivity analysis. The problem is discussed in the context of incentive regulation used by the Federal Communications Commission in the United States and the appropriate correction is indicated. An example of the problem and its correction, using the access charge for interstate service in telecommunications, is provided. The correction shows that the appropriate X-factor is 12 percent greater than that based on conventional growth accounting total factor productivity analysis. Copyright Kluwer Academic Publishers 2002