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Assumptions and Data Conventions

World Economic Outlook Database

Last Updated: April 18, 2017

The World Economic Outlook (WEO) database contains selected macroeconomic data series from the statistical appendix of the World Economic Outlook report, which presents the IMF staff's analysis and projections of economic developments at the global level, in major country groups and in many individual countries. The WEO is released in April and September/October each year.

This site provides the most frequently requested information from the WEO database consistent with the data published in the World Economic Outlook.


A number of assumptions have been adopted for the projections presented in the World Economic Outlook (WEO). It has been assumed that real effective exchange rates remained constant at their average levels during February 1 to March 1, 2017, except for those for the currencies participating in the European exchange rate mechanism II (ERM II), which are assumed to have remained constant in nominal terms relative to the euro; that established policies of national authorities will be maintained (for specific assumptions about fiscal and monetary policies for selected econo­mies, see Box A1 in the Statistical Appendix); that the average price of oil will be $55.23 a barrel in 2017 and $55.06 a barrel in 2018 and will remain unchanged in real terms over the medium term; that the six-month London interbank offered rate (LIBOR) on U.S. dollar deposits will average 1.7 percent in 2017 and 2.8 percent in 2018; that the three-month euro deposit rate will average –0.3 percent in 2017 and –0.2 percent in 2018; and that the six-month Japanese yen deposit rate will yield on average 0.0 percent in 2017 and 2018. These are, of course, working hypotheses rather than forecasts, and the uncertainties surrounding them add to the margin of error that would in any event be involved in the projections. The estimates and projections are based on statistical information available through April 3, 2017.

Data Conventions

Data and projections for 192 economies form the statistical basis of the WEO database. The data are maintained jointly by the IMF’s Research Department and regional departments, with the latter regularly updating country projections based on consistent global assumptions.

Although national statistical agencies are the ultimate providers of historical data and definitions, international organizations are also involved in statisti­cal issues, with the objective of harmonizing meth­odologies for the compilation of national statistics, including analytical frameworks, concepts, definitions, classifications, and valuation procedures used in the production of economic statistics. The WEO database reflects information from both national source agencies and international organizations.

Most countries’ macroeconomic data presented in the WEO conform broadly to the 1993 version of the System of National Accounts (SNA). The IMF’s sector statistical standards—the sixth edition of the Balance of Payments and International Investment Position Manual (BPM6), the Monetary and Financial Statistics Manual (MFSM 2000), and the Government Finance Statistics Manual 2014 (GFSM 2014)—have been or are being aligned with the SNA 2008. These standards reflect the IMF’s special interest in countries’ external posi­tions, financial sector stability, and public sector fiscal positions. The process of adapting country data to the new standards begins in earnest when the manuals are released. However, full concordance with the manuals is ultimately dependent on the provision by national statistical compilers of revised country data; hence, the WEO estimates are only partially adapted to these manuals. Nonetheless, for many countries the impact, on major balances and aggregates, of conversion to the updated standards will be small. Many other countries have partially adopted the latest standards and will continue implementation over a period of years.

Note: Many countries are implementing the SNA 2008 or European System of National Accounts (ESA) 2010, and a few countries use ver­sions of the SNA older than that from 1993. A similar adoption pat­tern is expected for the BPM6 and GFSM 2014. Please refer to Table G in the Statistical Appendix, which lists the statistical standards adhered to by each country. 

The following conventions have been used throughout the WEO:

  • Domestic economy series are expressed in billions of national currency units
  • External accounts series are expressed in billions of U.S. dollars.
  • "Billion" means a thousand million; "trillion" means a thousand billion.
  • Missing data are indicated by "n/a".
  • Blank row means that data are not available or not applicable.
  • "/" means between years or months (for example, 2016/17) to indicate a fiscal or financial year.
  • Shading differences are used to distinguish historical results from IMF staff projections.
  • Minor discrepancies between sums of constituent figures and totals shown reflect rounding.
  • Data refer to calendar years, except in the case of a few countries that use fiscal years. Please refer to Table F in the Statistical Appendix, which lists the economies with exceptional reporting periods for national accounts and government finance data for each country.
  • For some countries, the figures for 2016 and earlier are based on estimates rather than actual outturns. Please refer to Table G in the Statistical Appendix, which lists the latest actual outturns for the indicators in the national accounts, prices, government finance, and balance of payments indicators for each country.
  • As used here, the terms “country” and “economy” do not in all cases refer to a territorial entity that is a state as understood by international law and practice. The term also covers some territorial entities that are not states but for which statistical data are maintained on a separate and independent basis.
  • Composite data are provided for various groups of countries organized according to economic characteristics or region. Unless noted otherwise, country group composites represent calculations based on 90 percent or more of the weighted group data.
  • Nauru is the latest country added to the WEO database, expanding it to a total of 192 countries.
  • Belarus redenominated its currency by replacing 10,000 old Belarusian rubles with 1 new Belarusian ruble. Local currency data for Belarus are expressed in the new currency starting with the April 2017 WEO database.

Further Information and Data

This version of the WEO is available in full through the IMF eLibrary ( and the IMF website ( Accompanying the publication on the IMF website is a larger compilation of data from the WEO database than is included in the report itself, including files containing the series most frequently requested by readers. These files may be downloaded for use in a variety of software packages.

The data appearing in the WEO are compiled by the IMF staff at the time of the WEO exercises. The historical data and projections are based on the information gathered by the IMF country desk officers in the context of their missions to IMF member countries and through their ongoing analysis of the evolving situation in each country. Historical data are updated on a continual basis as more information becomes available, and structural breaks in data are often adjusted to produce smooth series with the use of splicing and other techniques. IMF staff estimates continue to serve as proxies for historical series when complete information is unavailable. As a result, WEO data can differ from those in other sources with official data, including the IMF’s International Financial Statistics.

The WEO data and metadata provided are “as is” and “as available,” and every effort is made to ensure their timeliness, accuracy, and completeness, but it cannot be guaranteed. When errors are discovered, there is a concerted effort to correct them as appropriate and feasible. Corrections and revisions made after publication are incorporated into the electronic editions available from the IMF eLibrary ( and on the IMF website ( All substantive changes are listed in detail in the online tables of contents. For details on the terms and conditions for usage of the WEO database, please refer to the IMF Copyright and Usage website.

Inquiries about the content of the World Economic Outlook and the WEO database should be sent by mail, fax, or online forum (telephone inquiries cannot be accepted):

World Economic Studies Division
Research Department
International Monetary Fund
700 19th Street, N.W.
Washington, DC 20431, U.S.A.

Fax: (202) 623-6343

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