Series’ codes used in the Economic Outlook statistical annex

1.2.6. Data processing

Variables are defined in such a way that they are as homogeneous as possible over the countries. Breaks in underlying series are corrected as far as possible. The following treatments are applied to national data, when necessary:  Back-splicing of data: For several countries, some historical data have been estimated by the OECD Economics Department; if countries revise their methodologies but only supply revised data for recent years, the historical data are estimated by mechanically linking the new and old series. Prior to the first year for which actual historical data are available, data have been spliced backward using the growth rates from the previous national accounts.  Calculation of chained volume measures: a common computation of chained volume measures, which may differ from national methodologies, has been introduced over the forecast period for most of the countries and the level of a particular volume aggregate is thus no longer the simple summation of the level of its components. Contributions to changes in real GDP, shown in the OECD Economic Outlook Annex table, but not included in the database release, have been based on a Laspeyres chain-type aggregation: the stock building contribution is computed as the weighted difference between the growth of real gross capital formation investment including changes in inventories and the growth of real gross fixed capital formation investment excluding changes in inventories, the weights reflect the share of the different components of GDP at current prices in the previous period; similarly, the net trade contribution is computed as the weighted difference between the growth of real exports and the growth of real imports, the weights reflect the share of the different components in GDP at current prices in the previous period. Data processing  Data import from various sources  Data checking  Break removals  Extension in the past  Calculation of indicators  Metadata, etc. National and international data bases  Annual and quarterly national accounts  Financial statistics  Labour force statistics  Balance of payments, etc. Economic Outlook  Expert judgement  Assessing current situation  Policy settings  Economic and statistical models  Analytical techniques, etc.  OECD Forecasts