Data and methods

Research outputs describe data sources, periods, statistical definitions, units, sample selection and principal processing steps. Third-party data retain their original name and URL. Restrictions arising from licences, confidentiality or personal information are stated together with the extent to which the data can be accessed.

The methods section identifies the research design, principal assumptions, variables or indicators, calculation steps, and software or models used. Quantitative results retain the formulae, parameters and version information required for review.

Each output states the limits of the data and methods, relevant uncertainty and plausible alternative explanations. Data that cannot be released do not justify omitting the basic account of the method.

Public datasets and code use stable URLs and state their version, licence and file details. External datasets are registered only from checked primary sources. The website does not copy material beyond the scope of its licence.

If a data or calculation error affects a conclusion, the text, attachments and citation files are corrected and the change is entered in the corrections register.