The reliability of the results derived from the comparable profit split is affected by the quality of the data and assumptions used to apply this method. In particular, the following factors must be considered –
(1) The reliability of the allocation of costs, income, and assets between the relevant business activity and the participants’ other activities will affect the accuracy of the determination of combined operating profit and its allocation among the participants. If it is not possible to allocate costs, income, and assets directly based on factual relationships, a reasonable allocation formula may be used. To the extent direct allocations are not made, the reliability of the results derived from the application of this method is reduced relative to the results of a method that requires fewer allocations of costs, income, and assets. Similarly, the reliability of the results derived from the application of this method is affected by the extent to which it is possible to apply the method to the parties’ financial data that is related solely to the controlled transactions. For example, if the relevant business activity is the assembly of components purchased from both controlled and uncontrolled suppliers, it may not be possible to apply the method solely to financial data related to the controlled transactions. In such a case, the reliability of the results derived from the application of this method will be reduced.
(2) The degree of consistency between the controlled and uncontrolled taxpayers in accounting practices that materially affect the items that determine the amount and allocation of operating profit affects the reliability of the result. Thus, for example, if differences in inventory and other cost accounting practices would materially affect operating profit, the ability to make reliable adjustments for such differences would affect the reliability of the results. Further, accounting consistency among the participants in the controlled transaction is required to ensure that the items determining the amount and allocation of operating profit are measured on a consistent basis.