No less than fit for purpose: Co-design with indigenous and other communities is ethical statistical practice

Ethical statistical practice requires a professional commitment to the “fitness for purpose” of both data and statistical products. While the UN Fundamental Principles of Official Statistics and the European Statistical System Code of Practice identify “relevance” as a core objective, the American Statistical Association (ASA) Ethical Guidelines frame “fitness for purpose” as an explicit ethical obligation. This paper argues that fitness for purpose constitutes a minimum ethical standard for all statistical practice, with critical implications for Indigenous data and other communities with specific needs, such as rare disease populations. We demonstrate that co-designing projects with Indigenous communities ensures data are fit for purpose and support sovereign decision-making. By embedding fitness for purpose throughout the statistical lifecycle, practitioners improve decision-making and avoid harmful deficit-based framings. Our analysis shows how operational tools such as the CARE Principles for Indigenous Data Governance and the UN Human Rights–Based Approach to Data, are realized through ethical practice and purposeful co-design. Finally, we present a tool for data projects to explicate intended purposes, enabling the fitness of data collection and statistical products to be systematically determined and documented across diverse stakeholder contexts.