k-Anonymity Explorer · Crown Dependencies Re-Identification Observatory

k-Anonymity. A dataset satisfies k-anonymity if every record shares its combination of quasi-identifying attributes with at least k–1 other records. The chart below shows what percentage of each island's population lives in groups of size ≥ k for a given set of quasi-identifiers (QIs). The k=1 intercept — where the line starts — is the uniqueness percentage: the share of residents who are the only person with that exact profile. As k rises, the protected share of the population falls. The steeper the drop, the weaker the anonymity.

Quasi-identifier set:

% of Population in Groups of Size ≥ k

k=1 intercept = uniqueness %. Jersey's larger population gives structural k-anonymity advantage despite having fewer areas.

Isle of Man

Guernsey

Jersey

Method · k-anonymity curves are derived from a synthetic population model calibrated to 2021 census distributions for each Crown Dependency. The model generates individual records matching published age, sex, occupation, and area marginals, then counts how many records share each quasi-identifier combination. These are pre-computed research findings — not live query results — and represent valid outputs from the synthetic population model even where full census microdata has not been requested. Uniqueness percentages and k-profiles will be updated when calibration data is received from Statistics IoM, Statistics Jersey, and Statistics Guernsey.