Using Old Data: When Is It Appropriate?

Researchers and gatekeepers lack clarity about the circumstances under which using old data to test hypotheses is appropriate or inappropriate. In response to this complex issue, we first define what makes data "old." We then suggest that using old data is justifiable (a) when examining a past event, (b) when recent data are not available, or (c) when the data were collected painstakingly. Scholars should avoid using old data if none of these conditions exist. Further, authors should be forthcoming about the age of their data and, in the case of a rejected journal submission, update the data whenever possible.