Coordinating Working Party on Fishery Statistics (CWP)

Data confidentiality

Confidentiality of certain data or data types may be required to protect personal and commercial interests. However, a confidentiality claim is justified only if there is a risk to reveal data that can be referred to individuals or legal entities. While CWP does not offer specific recommendations on how best to deal with confidentiality claims, there are the following general guidelines. Data for which confidentiality is requested fall into two groups: microdata and data that are already aggregated.

Microdata refer to data items that directly refer to individuals or legal entities.

Aggregated data may present a risk for revealing the origin of the data but this risk is less than for microdata.

An analysis of how well founded a confidentiality claim is, is based on the key characteristics of the data, use of the data and what disclosure risks need to be protected against. Among the key characteristics of the data particular attention needs to be paid to the dissemination methods. To determine whether a statistical unit is identifiable, account must be taken of all means that might reasonably be used by a third party to identify such a statistical unit. Working with confidential data requires procedures that protect against misuse of the data. These procedures should be established by the organization that collects and processes the data and implementation of such procedures is often a prerequisite for the access to data. Microdata may be used internally in the processing organization for e.g. scientific purposes without revealing the data in detail.

The format and dissemination methods in which data can be published need to be considered to protect the data and Hundepool et al 2010 and references found in this report summarize appropriate methods. See also the FAO background documents to this Handbook.

Resources for data confidentiality

Hundepool, A., Domingo-Ferrer, J., Franconi, L., Giessing, S., Lenz, R., Naylor, J., Nordholt, E.S., Seri, G. & De Wolf, P.-P. 2010. Handbook on statistical disclosure control. ESSNet-handbook SDC Version 1.2. Eurostat. 216 pp. (also available at

UNECE. 2007. Managing statistical confidentiality and microdata access - principles and guidelines of good practice. New York and Geneva, UN. 108 pp. (also available at

World Bank. 2011. Global strategy to improve agricultural and rural statistics. Report No. 56719-GLB. Washington, DC, World Bank and Rome, FAO. 39 pp. (also available at