About PWT Mark 6.1

Main Differences between PWT6.1 and Previous Versions

1. New users of  PWT should check the description of the variables in the Appendix. 
2. Users of preliminary PWT6: Originally, PWT6 was to be issued in a final form in this site. Users provided many helpful comments. Tony Swan and Steve Dowrick of Australian National University deserve special mention for catching some important errors. By the time corrections were made we were able to update to 2000 (see National Accounts below). To avoid possible confusion we are calling this version PWT6.1.
3. For users of  PWT 5.6 or earlier versions, we list below some of the major differences.

• Base Year: In PWT 6.1, the base year is 1996, so all constant price series will be substantially higher than PWT 5.6
• National Accounts: Many of the underlying national accounts of countries will have been revised since 1995 and these changes have  been incorporated in the new version. PWT6.0 was mainly based on the World Development Indicators (WDI) 2000  disk, while PWT6.1 uses the WDI 2002 national accounts for non-OECD countries, and the OECD 2002 (see Electronic Publications and National Accounts of OECD countries: Main Aggregates 1970/2000 2002 Edition Volume 1) national accounts for 30 OECD countries.  Data for years not in the WDI or OECD disks are obtained from previous national accounts files used in PWT5.6 and earlier versions. The underlying National Accounts files for PWT6.1 (current and constant 1996 series in local currencies for GDP components) is now provided as a file (see Downloads) with the permission of the World Bank and the OECD. 
• The base year international prices of Consumption, Investment and Government are based on information in the 1996 benchmark estimates as well as earlier benchmark or short-cut estimates.  Many countries in previous versions that were estimated by short-cut estimates are now based on benchmark estimates that we consider more reliable.  These new international prices may also change the growth rates of countries from previous versions of PWT.
• Physical Capital Stock Estimates: A new set of capital stock estimates are being developed for PWT 6.1, and these will be added as they become available.  Initially we will just include the OECD countries.  As in PWT 5.6 there will be detailed estimates for about 60 countries.  We also plan to extend physical capital stock estimates to a larger number of countries at an aggregate level.
• Terms of Trade: In place of the terms of trade variable in PWT 5.6 we will provide a measure of Gross Domestic Income of each country per capita.  This variable will adjust constant price GDP for trading gains and losses, following the 1993 System of National Accounts.  This adjustment computes Gross Domestic Income as Domestic Absorption in 1996 prices plus current exports minus imports deflated by the national accounts deflator and the 1996 PPP of Domestic Absorption. 
• China: Because estimates of PPPs and growth rates for China are very important for understanding the world economy, but also subject to error, we have described our estimates in a separate China Appendix. 
• Taking Account of Earlier Base Year Estimates:  In previous versions of PWT we have estimated base-year international prices taking account of information from earlier benchmarks.  In this version a similar procedure was carried out for both benchmark and non-benchmark countries as described in the data Appendix.
• Non-Benchmark Countries: The treatment of non-benchmark countries is slightly different than earlier versions of PWT. These are described in the data Appendix.
•  Additional Variables: We have included a national accounts definition of saving on an international basis, but the user should understand that it does not necessarily measure effort of countries to sacrifice current consumption.
• Country Grades:  As in some earlier versions, we have assigned grades to the quality of our estimates based on the extent of benchmark participation by countries and other variable described in the data Appendix.  The basic inputs into our judgment are provided so that users may come up with alternative measures of data quality.
• Geographic Code: In previous versions, countries were presented alphabetically by continent.  While these could be easily sorted in other ways, in PWT 6 we have chosen to present all countries alphabetically by ISO. That code is itself not always transparent so we have also presented an alphabetical list of countries in English with the corresponding ISO 3-digit code.  We have also classified countries by 15 geographical regions of the world that may be an aid to users (see Country Codes in Downloads).