OECD

Valentina Romei

Markets promptly react to flash releases of economic indicators and large sums of money are lost or made based on zero-point-something percentage points of GDP growth. But, in the excitement of new economic data, it is worth remembering how data is subject to frequent and quite substantial revisions.

Notoriously, in 2010 Japan’s most watched economic indicator was drastically revised downwards, slicing off a full 3.5 percentage points from the annualised growth rate first reported for the third quarter of 2009, prompting soul searching about the quality of Japanese economic data. But revisions occur across many countries and not only after the flash releases.

An OECD database of the various edition of the monthly publication of the Main Economic Indicators (MEI) shows how widespread the issue is. Read more