Revisions of National Accounts (the basis for STAN) {#revision}

In recent years, many countries have completely revised their National Accounts - usually to conform to recommendations outlined in System of National Accounts, 1993 (SNA93) or, in Europe, ESA95. Previously SNA68 was the standard. The main differences are outlined below. Additional information on historic versions of the System of National Accounts can be found on the U.N. Statistics Division homepage.

Change in industrial classification

In line with the 2008 revision of SNA93 (ESA95) many countries have adopted ISIC Rev.4 (NACE Rev.2) to classify activities and although there are many similarities in the industry descriptions of ISIC Rev.4 and ISIC Rev.3 (the previous standard for SNA93), there are many significant differences in the detailed activities included (see UNSD Correspondence Tables). Therefore, even without changes in definitions of variables, differences would be apparent between recent and previous National Accounts based data sets such as STAN.

Changes in variable definitions

There have been important changes in definitions of variables, most notably: Valuation of Value Added - most countries (particularly in Europe) now provide Value Added at Basic Prices. Previously, some used the concept of Producer's Prices or Factor Costs;

• Treatment of software purchases: software is now considered as an investment good, hence GFCF figures may be higher than before, particularly in heavy ICT using sectors. Previously, it was considered as an intermediate input. Removal of software from intermediate inputs increases Value Added; Use of chained volumes - Previously, most countries calculated output (and investment) volumes by using fixed base Laspeyres aggregation (hence the term ``GDP at constant prices''). Some countries now provide annually re-weighted chained volumes, and more are expected to do so in the near future;
• Use of quality adjusted or "hedonic" deflators: the recent use of such deflators for ICT products is concentrated in a few countries (for example, USA, Japan, France and Denmark) and significantly alters the profile of output deflators in ICT industries compared with using prices of ICT products based on transitional deflating methods (see OECD STI Working Paper 2004/9: Handbook on Hedonic Indexes and Quality Adjustments in Price Indexes: Special Application to Information Technology Products).
• Capital Stock estimates: asset type breakdowns have been expanded in many countries (e.g. to separate ICT and software goods) which affects estimation of capital stocks by industry. Also, many countries have refined their methodologies (for example, introducing new estimates of retirement patterns or average service lives);
• Output of services: there is a general effort in many countries to improve direct measurement of the output of services. For example, the practice of estimating real output for services using input measures (such as employment), particularly for public sector, greatly limits the validity of productivity indicators for the industries concerned.

Survey based activity data in NACE Rev.1 {#nace1}

Since the mid-1990s European countries have been collecting and publishing industry survey statistics according to NACE Rev.1. Few, if any, attempts are made to convert previous survey results based on old national classifications, to NACE Rev.1 so long time-series are not generally available. Similarly, in North America, survey data are now collected according to the North American Industrial Classification System (NAICS).