Revision policy of the National Statistics Institute

Revisions of data constitute a practice that is inherent to the production of statistics, and there are two types:

  • - Ordinary or routine revisions. For some statistics, in which users particularly value having data as soon as possible, the initial estimates are published with the expectation that they might be revised and updated when new data is available. This is characteristic of short-term statistics, such as the monthly or quarterly statistics.
  • - Large revisions. Revisions also follow changes in data sources, in concepts, definitions and classifications, or due to an improvement in methodological procedures. By nature, these revisions have a greater impact on the data, though they are also performed less frequently.

Moreover, there are other data revisions that are not planned, and which are due to the need to correct errors in previously disseminated statistics. In fact, despite the quality control procedures and measures adopted, it is inevitable that errors will occur in the information published: this gives rise to unplanned or extraordinary revisions.

The general document on the Revision Policy of the INE approved by the Board of Directors at its meeting on 13 March 2015, establishes common criteria and norms for INE statistics, when introducing revisions to the data published, for any of the aforementioned reasons. With the adoption of this policy, the INE meets user requirements for transparency and information, as recommended in the European Statistics Code of Practice.

It is important to indicate that, in the INE, there are specific revision policies for different statistical operations, in some cases defined in the corresponding European regulations. (The details on revision policies existing in specific fields may be viewed at the websites for each of the statistics. A summary of the criteria used is included in the Standardised Methodological Reports sections 19.1 and 19.2).

However, there was no homogeneous global framework establishing common norms and principles for the whole of the INE production, and this deficiency has been remedied with this general document on Revision Policy.