COHERENCE OF THE NATIONAL ACCOUNTS
Coherence of statistical data includes coherence between different data items pertaining to the same point in time, coherence between the same data item for different points in time, and international coherence.
By being aware of the factors that influence coherence, judgements can be made as to the extent of error that might be associated with an estimate. These judgements can be enhanced by comparing estimates that conceptually should be identical, or by comparing estimates where a particular relationship between the estimates could be expected. In other words, the extent to which a set of statistics are coherent can provide a guide to the accuracy of the statistics. However, it should be noted that a coherent set of statistics is not necessarily an accurate set, as the statistics that are being compared may suffer from similar magnitudes of error with the errors being in the same direction.
Users are sometimes faced with utilising different sets of statistical information derived from different sources and at different times. Appropriate use is facilitated if information can be validly compared with other related data sets. This is achieved through the use of common, or at least comparable, concepts and methodologies across products. The tools for managing coherence fall under three broad headings.
Standard frameworks, concepts, variables and classifications
These aim to ensure that the target of measurement is consistent across statistical programs, that consistent terminology is used across programs and that the qualities being estimated bear known relationships to each other. The realisation of this element is normally through the adoption and use of frameworks such as the SNA and the ASNA. The issue of international comparability is addressed by considering the adherence of the standards adopted to the international standards as contained in the SNA.
Although there are a wide range of uses for economic data, national accounts data requirements are a key guiding principle behind most of the ABS's economic collections. Coherence has been aided by the harmonisation of the various international standards for economic statistics with the SNA. Where administrative data are used, special care is taken to ensure the correct application of standards and the identification of possible data gaps and overlaps. Where administrative data are known to differ from national accounts standards, appropriate adjustments are made to align the data.
Common frames, methodologies and systems
The development and use of common frames, methodologies and systems for data collection and processing contribute to data coherence. For example, the use of a common business register across all business surveys ensures that differences in frame coverage do not introduce inconsistencies in data; the use of commonly formulated questions when the same variables are being collected in different surveys serves to minimise differences due to response error; the use of common methodology and systems for the various processing steps of a survey helps to ensure that these operations do not introduce discrepancies in data.
This page last updated 30 August 2007