Detecting Fake People in Historical Records

Abstract Data quality is a key input in efforts to link individuals across census records. We examine the extreme case of low data quality by identifying US census enumerators who fabricated entire families. We provide clear evidence of fake people included in the 1920 US Census for Homestead, Pennsylvania. We use the features of this case study to identify other places where information in the census may have been falsified. We develop an automated approach that identifies census sheets that have much lower match rates to other census records than would be expected, given the characteristics of the people recorded on each sheet. We perform a hand-check on the suspicious sheets using standard genealogy tools and identify at least 90 sheets where the entire census sheet appears to have been fabricated.