2.1. Accuracy was defined above as the proximity of an estimate to some notional true value. Because the true value cannot be determined, the accuracy of an estimate can not be measured objectively. However, as a practical alternative, the final or fully-revised estimate made by the statistician is taken to be the best approximation of that true value. Because the Australian balance of payments is, in principle, always subject to further revision, the notion of a final estimate is also not strictly appropriate. In these circumstances and for the purposes of this analysis, the assumption is made that the most recent estimate made from relatively final source data is the best available estimate of the true value.
2.2. Because the balance of payments draws data from a wide variety of sources, each providing data of varying degrees of conceptual correctness and completeness, it is not possible to produce a single overall measure of accuracy of the accounts. Instead, assessments have to be made of individual component items within the accounts. Even at this level, the use of multiple data sources in estimating a single item, their variable accuracy over time, and changing compilation methods complicate the picture. As a result, assessment of the accuracy of an item depends substantially on a subjective judgement based on knowledge of the sources, data and compilation methods used.
2.3. There are a number of specific indicators and influences to be taken into account in reaching a judgement on the accuracy of the data. These are discussed in the following paragraphs.