Measures of Disclosure Risk and Harm

Diane Lambert

Abstract:
Disclosure is a difficult topic. Even the definition of disclosure depends on the context. Sometimes it is enough to violate anonymity. Sometimes sensitive information has to be revealed. Sometimes a disclosure is said to occur even though the information revealed is incorrect. This paper tries to untangle disclosure issues by differentiating between linking a respondent to a record and learning sensitive information from the linking. The extent to which a released record can be linked to a respondent determines disclosure risk; the information revealed when a respondent is linked to a released record determines disclosure harm. There can be harm even if the wrong record is identified or an incorrect sensitive value inferred. In this paper, measures of disclosure risk and harm that reflect what is learned about a respondent are studied, and some implications for data release policies are given.

Keywords:
Anonymity; confidentiality; disclosure threat; identification; linking, masked data; security.