Monopsony power and the existence of natural monopoly in energy utilities

The justification for price and entry regulation of firms hinges on whether the firms are natural monopolies, and empirical tests have been used to determine the natural monopoly status of public utilities. However, these tests are biased if the utilities possess monopsony power - a likely case. The bias is against finding natural monopoly status, which can lead to improper policies. An alternative method of testing is proposed which eliminates the bias.