Where can I find electronic versions of the tables in World Development Indicators?
Electronic versions of the data tables in the WDI print edition are available in our World Development Indicators CD-ROM.
Which data set should I use?
Historical data in the World Development Indicators (WDI) database often changes with each edition. We advise clients to use our most current data set since it provides not only data for the latest year available, but also revisions to previously published data. In most cases, revisions are due to estimates becoming more robust over time given better collection methods and more recent surveys. Changes in methodology or changes in data source are also possible. In certain instances, data which have been determined to be questionable may be deleted. Our standard practice is to preserve historical time-series as much as possible. In a very few cases, revisions to time-series sometimes cause breaks in series which cannot be reconciled by linking or other estimation techniques. Therefore each new edition of WDI contains the most complete time series we have currently available, and gap-filling from previous editions is inadvisable.
For example, in 1998 the United Nations Educational, Scientific and Cultural Organization (UNESCO) introduced the new International Standard Classification of Education 1997. Over the past few years, in a number of cases, UNESCO has removed previously reported data for the years before 1997 since they were no longer consistent with those for 1998 and later. Using the latest September 2007 update to the WDI database is particularly important for literacy series, as UNESCO has now placed its estimates under the actual data year for each country rather than placing all recent estimates under the year 2006. The reported literacy data are compiled by the UNESCO Institute for Statistics based on national censuses and household surveys during 1995-2005. The data for earlier years are based on model estimations. Therefore the data for earlier and later years may not be comparable. The estimation methodology and other information about UNESCO education series can be reviewed here.
Another example is the government finance data we receive from the International Monetary Fund (IMF). The earlier set of data reported in World Development Indicators conform to definitions and guidelines in the IMF’s Government Finance Statistics (GFS) manual of 1986. The current set of data is based on the definitions and guidelines in GFS 2001 manual. The IMF has switched the methodology to conform to the 1993 System of National Accounts. The main difference between the two methods is that the earlier 1986 method is a cash-based method, whereas the 2001 method is based on accrual accounting. Further, the IMF has reclassified historical data to conform to the new format, and in some cases data which could not be reconciled has been removed.
For more details about the differences in the two reporting methods please see the “About the data” sections for Tables 4.10 to 4.12 in the WDI, and the IMF's GFS manual 2001.
Why are there discrepancies between the Quick Reference tables and the WDI Online database?
Our World Development Indicators (WDI) database, where the data for the Quick Reference Tables come from, is updated twice a year (April and September). However, the World Bank's operational and analytical classification of economies based on the latest data is set on July 1 of each year to comply with the Bank's fiscal year. Thus, we release data for GNI, GDP and population earlier than the WDI database update. These GDP and GNI figures are in current prices and are not fully consistent with the data available in the WDI database between July and September. When we update the database in September to include the most recent data, historical series are also revised and adjusted to be consistent with the recent data. We strongly recommend our users not to use these preliminary Quick Reference numbers in combination with the historical data currently in our WDI database during the July to September period.
Why are there discrepancies between the WDI CD-ROM and the WDI Online database?
Our World Development Indicators online database is updated twice a year (April and September). The April update is a major one, and the edition of the database changes. New indicators might be added and some might get deleted. The WDI CD-ROM is based on the April update. The September update for WDI online includes preliminary estimates of main indicators for the most recent year available (which will be one year later than the last year shown on the CD-ROM) and may also include revisions to historical data previously published.
Which publication should I buy: the World Development Indicators or Global Development Finance?
The WDI contains a comprehensive set of indicators related to development topics and is organized into sections on World View, People, Environment, Economy, States and Markets, and Global Links. The GDF focuses on debt containing data on total external debt stocks and flows, aggregates and key debt ratios, and provides a detailed, country-by-country picture of debt. Please note that each publication is available in a variety of formats (print, CD-ROM and online). More information on this can be viewed for the WDI and for the GDF respectively.
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