Many existing data sets are made publicly available for further analysis. One of the main sources of such data is the federal government (e.g., Bureau of Labor Statistics). It should be noted that, increasingly, federal agencies require that researchers make data collected with assistance of federal funds available to the public. In addition, social science professional organizations and journals may require that researchers make data sets used for the production of published scholarly papers accessible in public use data files to encourage scholarly replication of research.

Under 45 CFR 46.101, projects may be designated exempt to such requirements under certain circumstances by the IRB. The following regulations apply:

(b) Unless otherwise required by department or agency heads, research activities in which the only involvement of human subjects will be in one or more of the following categories are exempt from this policy

(4) Research involving the collection or study of existing data, documents, records, pathological specimens, or diagnostic specimens, if these sources are publicly available or if the information is recorded by the investigator in such a manner that subjects cannot be identified, directly or through identifiers linked to the subjects.