System of National Accounts

The System of National Accounts (often abbreviated as SNA; formerly the United Nations System of National Accounts or UNSNA) is an international standard system of national accounts, the first international standard being published in 1953. Handbooks have been released for the 1968 revision, the 1993 revision, and the 2008 revision. The System of National Accounts, in its various released versions, frequently with significant local adaptations, has been adopted by many nations. It continues to evolve and is maintained by the United Nations, the International Monetary Fund, the World Bank, the Organisation for Economic Co-operation and Development and the Statistical Office of the European Communities

The aim of SNA is to provide an integrated, complete system of accounts enabling international comparisons of all significant economic activity. The suggestion is that individual countries use SNA as a guide in constructing their own national accounting systems, to promote international comparability. However, adherence to an international standard is entirely voluntary, and cannot be rigidly enforced. The systems used by some countries (for example, France, United States and China) differ significantly from the SNA. In itself this is not a major problem, provided that each system provides sufficient data which can be reworked to compile national accounts according to the SNA standard.

Economic and financial data from member countries are used to compile annual (and sometimes quarterly) data on gross product, investment, capital transactions, government expenditure and foreign trade. The results are published in a UN Yearbook, National Accounts Statistics: Main Aggregates and Detailed Tables, which currently (and until the 2008 revision comes into force) follows the 1993 recommendations. The values provided are in the national currency.

Additionally, national statistical offices may also publish SNA-type data series. More detailed data at a lower level of aggregation is often available on request. Because national accounts data is notoriously prone to revision (because it involves a very large number of different data sources, entries and estimation procedures impacting on the totals), there are often discrepancies between the totals cited for the same accounting period in different publications issued in different years. The "first final figures" may in fact be retrospectively revised several times because of new sources, methods or conceptual changes. The yearly revisions may be quantitatively slight, but cumulatively across e.g. ten years they may alter a trend significantly. This is something the researcher should bear in mind in seeking to obtain a consistent data set.

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