The accountant of today must be particularly firm in his contention that costs incurred in a given year must be charged to that year and carried forward only in those cases where they will definitely benefit the future. This applies to cost of idleness and would prohibit its deferral by any such process as omitting the charge for depreciation because the equipment was not productive. It is also inadvisable to charge the costs of idle equipment direct to surplus on the grounds that such costs were not an element in the production of that particular period's income. One of the principal features of the current order of things which raises accounting problems is the lowered price level. Accounting involves both the establishment of a correct income estimate and the periodic showing of the financial condition of the concern for which those earnings are estimated. For such purposes, replacement values have a place unless the statement is to be merely historical in character. In a period of rising prices the use of a depreciation charge based upon cost leads to an overly optimistic attitude by the persons relying upon our estimates whether they be managers, investors or creditors. In periods of falling prices the effect is undue pessimism.