This approach is employed because the value of the asset may fluctuate between the time the asset is purchased and the time it is sold or junked. Attempts to measure these interim value changes have not been well received because values are difficult to measure objectively. Therefore, Enhance Electronics charges the asset's cost to depreciation expense over its estimated life. It makes no attempt to value the asset at fair value between acquisition and disposition. Companies use the cost allocation approach because it matches costs with revenues and because fluctuations in fair value are uncertain and difficult to measure.