SNtable
Revisions to PPP-based GDP across World Bank ICP rounds
Change in each economy’s GDP at PPP relative to the United States, in percent. Positive = economy looks larger.
A. Revision when a new ICP round arrives
The new benchmark for the reference year compared with the World Bank’s estimate for that year in its last release before the round (extrapolated from the previous benchmark).
| Economy | 2005 | 2011† | 2017 | 2021 | Typical (RMS) | Largest | Exchange-rate swing‡ | Ratio |
|---|---|---|---|---|---|---|---|---|
| Revision when the new ICP round arrived (%) | Size of revisions (%) | Comparison | |||||
Emerging markets | ||||||||
China | −39.5 | +20.7 | −15.7 | +4.7 | 23.8 | 39.5 | 7.4 | 3.2× |
Thailand | −20.4 | +43.1 | −3.0 | +7.4 | 24.2 | 43.1 | 8.1 | 3.0× |
Advanced economies | ||||||||
Japan | −1.8 | 0.0 | −2.8 | 0.0 | 1.6 | 2.8 | 14.2 | 0.12× |
United Kingdom | −4.7 | 0.0 | +1.3 | 0.0 | 2.5 | 4.7 | 9.7 | 0.25× |
Switzerland | −1.8 | 0.0 | +1.1 | 0.0 | 1.0 | 1.8 | 9.6 | 0.11× |
Korea | −3.7 | 0.0 | −0.7 | 0.0 | 1.9 | 3.7 | 8.5 | 0.22× |
B. Later revision of the published benchmark
The benchmark figure as first published compared with the figure for the same year after the next ICP round, and in today’s data (WDI, July 2026).
| Economy | At next round (ICP 2011) | Today | At next round (ICP 2017) | Today | Today (after ICP 2021) | Today |
|---|---|---|---|---|---|---|
| 2005 benchmark | 2011 benchmark | 2017 benchmark | 2021 benchmark | ||
Emerging markets | ||||||
China | +20.5 | +21.8 | −0.5 | −0.5 | +3.6 | 0.0 |
Thailand | +42.9 | +40.5 | −0.1 | −0.1 | +3.7 | 0.0 |
Advanced economies | ||||||
Japan | 0.0 | 0.0 | 0.0 | 0.0 | +0.3 | −0.5 |
United Kingdom | 0.0 | −10.1 | −1.1 | −1.1 | −0.4 | −3.6 |
Switzerland | 0.0 | +3.3 | +3.1 | +3.1 | −0.7 | −1.0 |
Korea | 0.0 | 0.0 | 0.0 | 0.0 | −0.1 | −0.3 |
Germany§ | n/a | n/a | −0.6 | −0.6 | −0.3 | −0.7 |
Notes: Revision = PPP_before / PPP_after − 1, holding GDP in local currency fixed; PPP = GDP PPP conversion factor (local currency per international $). Releases compared in panel A: Sep 2007 vs Apr 2014 (ICP 2005); Apr 2014 vs Jan 2015 (ICP 2011); Feb 2020 vs Dec 2020 (ICP 2017); Mar 2024 vs Jun 2024 (ICP 2021). Panel B: as-first-published values are taken from the Apr 2014 release for 2005 (still the ICP 2005 benchmark; China 3.448, matching the published 3.45), Jan 2015 for 2011, Dec 2020 for 2017 and Jun 2024 for 2021. UK 2005 “Today” (−10.1%) reflects a revision between the Jan 2015 and Feb 2020 releases.
Typical (RMS) = root mean square of the four revisions. Largest = largest absolute revision. On a log basis, China’s typical revision is 28% and 3.8× its exchange-rate swing.
† For OECD economies the 2011 figure is zero because their Eurostat–OECD 2011 benchmark PPPs were already in the World Bank’s April 2014 release, before ICP 2011 was published; these economies are re-benchmarked on a three-year cycle. Likewise, ICP 2021 left their 2021 figures unchanged; the small changes since then (panel B) come from later Eurostat–OECD updates.
‡ Exchange-rate swing = root mean square deviation of the log official exchange rate against the US dollar from a log-linear trend, 1999–2024 (World Bank WDI, PA.NUS.FCRF).
§ Germany appears in panel B only. It is not in the archive extract; its figures come from monthly copies of the WDI series in the datahub.io GitHub mirror (github.com/datasets/ppp), which match the archive to within 0.01% for the other economies. These copies start in 2015 and have a gap from Aug 2018 to May 2021, so Germany’s 2005, 2011 and 2017 ICP-round revisions cannot be measured; at the ICP 2021 release its PPP was unchanged (0.0%). Euro exchange-rate swing (1999–2024): 12.7%. 2011 first publication: Oct 2015 release. France, Italy, Spain: 0.0% at ICP 2021; later benchmark revisions −2.6% to +1.3%.
Source: World Bank, World Development Indicators Database Archives (releases Sep 2007 – Jul 2026) and WDI copies in the datahub.io mirror (Oct 2015 – Apr 2026); author’s calculations.
-- Sohaib Nasim, Oct. 19, 2026