The Eighth Circuit concluded that the utility had not attempted to change its treatment of a "class of assets." Rather, because the utility had consistently
expensed similar items, the court held that the mistake was no more than a posting error, which the utility could correct without IRS consent.
Although the period in which an expenditure is incurred may differ from the period of the activity creating the liability, permitting a current deduction is consistent with the requirement that taxable income be computed based upon the taxpayer's books and records because, for book purposes, these expenditures are generally
expensed. It is also consistent with the concept of economic performance prescribed by section 461(h).