476.52  Management efficiency.
  It is the policy of this state that a public utility shall operate in an efficient manner. If the board determines in the course of a proceeding conducted under section 476.3 or 476.6 that a utility is operating in an inefficient manner, or is not exercising ordinary, prudent management, or in comparison with other utilities in the state the board determines that the utility is performing in a less beneficial manner than other utilities, the board may reduce the level of profit or adjust the revenue requirement for the utility to the extent the board believes appropriate to provide incentives to the utility to correct its inefficient operation. If the board determines in the course of a proceeding conducted under section 476.3 or 476.6 that a utility is operating in such an extraordinarily efficient manner that tangible financial benefits result to the ratepayer, the board may increase the level of profit or adjust the revenue requirement for the utility. In making its determination under this section, the board may also consider a public utility’s pursuit of energy efficiency programs. The board shall adopt rules for determining the level of profit or the revenue requirement adjustment that would be appropriate.
  The board shall also adopt rules establishing a methodology for an analysis of a utility’s management efficiency.
83 Acts, ch 127, §35; 89 Acts, ch 297, §11