The Statistics Authority welcomes the growing number of comprehensive government datasets that are readily accessible online. These provide opportunity for people to examine and analyse for themselves the raw information available to government. However, this does not diminish the continuing importance of preparing and publishing professional statistical advice, in the form of a narrative commentary, alongside a summary of the official statistics at the time they are first released. The many organisations that produce official statistics should, in the public interest, always take appropriate steps to support the beneficial use of their statistical information inside and outside government.

The importance of this aspect of government statistical work is reflected in the requirements of the Code of Practice for Official Statistics which was introduced in January 2009. Compliance with the Code is a statutory requirement in relation to all statistics that are designated as National Statistics and is the good practice standard for all other official statistics.

Similarly, the Statistics and Registration Service Act 2007 defines the public good in relation to official statistics to include ‘informing the public about social and economic matters’ and ‘assisting in the development and evaluation of public policy’. Both of these things require that the statistics should be well explained.

The written text to accompany statistics at the time of their release needs to cover two types of information:

  • Descriptive material which sets out the relevant facts about the statistics such as time periods, geography, methods, definitions, other possible data sources, discontinuities and various other points to note.
  • Narrative commentary drawing out the main messages from the statistics, explaining the relevance of the statistics in terms of the policy context, stating assumptions about the use that will be made of the statistics and highlighting their strengths and limitations in relation to those uses.

Among the Code of Practice requirements are that producers of official statistics should prepare full and frank commentary and analysis that aid interpretation including:

  • information on the quality and reliability of statistics in relation to the range of potential uses
  • information on methods, procedures and classifications • factual information about the policy or operational context
  • formats for the presentation of statistics in graphs, tables and maps that enhance clarity, interpretability and consistency.

The Code further requires that the content of statistical releases is the sole responsibility of the relevant statistical Head of Profession in the organisation that is responsible for the statistics. There are strong arguments why government statisticians should give high priority to this work. In determining the resources to be devoted to, and content of, written commentary, consideration should be given to these points:

  • Official statistics only justify their production when they are used in ways that provide public benefit. That use might be inside or outside government. Most official statistics require careful explanation. Government statisticians will usually know the strengths and weaknesses of the statistics better than other commentators.
  • The cost of supplementing the production of statistics with text and other material that guides the user is relatively small, particularly in cases where statistics are produced in a regular series and the guidance is updated at each release. It is likely to be more efficient, in terms of the return on public investment in statistics, to offer written guidance to the user than not to do so.
  • Government statisticians share a common training and an ethos of impartiality. Whilst experts outside government are of course capable of writing impartial commentary, they are not under any obligation to do so. The statistical text written by government statisticians is subject to training, rules and controls aimed specifically at avoiding partisan comment.
  • Guidance to the user is needed most at the moment the statistics are first made public. The news media look to the statistical release to provide an objective account of the statistics. They may regard the absence of such text as indicative of partisan influence.
  • In the view of the Statistics Authority, the public has a right to know the statisticians’ understanding of the messages from the statistics, just as they have a right to the data itself. It is common, and proper, for statisticians in government departments to brief policy colleagues on the substance of the statistics. That knowledge should, as a matter of principle, be shared more widely.