2410 Germany the taxpayer but also a sword of the tax auditors as the requirement of consistency is itself limited by the criterion of abus The administrative principles do not provide for a certain concept of price anges, as for instance an interquartile price range under the U.S. Regulations. 29 However, if the taxpayer chooses a range of third party gross or net margins, it should be considered to exclude companies in the lower or upper end of the range of net or gross margin, since information is rather limited and extraordinary influ ences are often difficult to determine (d Aggregation of Transactions and Multiple-Year Analys The German tax administration has a clear preference for a transactional ap proach. Section 2. 1. 2. of the administrative principles emphasizes that the transfer price analysis should be based on every single transaction. If one would follow the wording of the administrative principles, this would go much further than the oECD, which also allows companies to aggregate certain transactions. However it is fair to assume that German principles allow for aggregation. since in many cases aggregation could be the only feasible approach to determine the transfer price. This is especially true in cases where the transactions are interrelated, mul- tiple transactions take place in a short period of time, or several transactions are part of a package deal Multiple-year analysis under certain conditions is supported by the OECD as well as by the U.S. tax administration. The multiple-year analysis is seen as a tool to analyze the effects of business or product life cycles and other business risk fac tors or influences that might have an effect on the transfer prices. These influences might better be judged over a longer period of time The administrative principles do not deal with multiple-year analysis. Such nalysis sometimes is rejected by tax auditors with the argument that it is agains a fundamental precept of German tax law that requires tax to be based on the nual accounting period(Prinzip der Abschnittsbesteuerung). Therefore, in ap- plying this analysis, the taxpayer and the tax auditor have to make sure that the profit situation of other closed periods does not lead to the conclusion that in come is too high or too low in the period under review. However, if the multiple year analysis is seen as a tool to judge the transfer prices of the current year( e. g for judging start-up losses, a market penetration strategy, or the long-term influence of currency risks), multiple-year analysis should not cause such See U.S. Regulations, $1.482-1(e)(2)(ini(c 3Kuckhoff/Schreiber, Verrechnungspreise in der Betriebspriifung, p. 74 3I See oECD Guidelines 31.42 32See OECD Guidelines 35 1.49-1.51; US Regulations, 3 1.482-I(f(2)(iii)