Associated enterprises are, however, able· to make a much greater variety of contracts and arrangements than can unrelated enterprises because the normal conflict of interest which would· exist between independent parties is often absent. Associated enterprises may and frequently do conclude arrangements of a specific nature that are not or are very rarely encountered between unrelated parties (cost contribution arrangements for research and development expenditure as discussed in Chapter III of the report would be one example). This may be done for various economic, legal or fiscal reasons dependent on the circumstances in a particular case. Moreover, contracts within an MNE could be quite easily altered, suspended, extended or terminated according to the overall strategies of the MNE as a whole and such alterations may even be made retroactively. In such instances tax authorities would have to determine what is the underlying reality behind an arrangement in considering what the appropriate arm’s length price would be.