2007 Classification Error Survey for the United States Census of Agriculture

Following the 2002 Census of Agriculture, a Classification Error Study was conducted to estimate the number of operations misclassified (either as farms or non-farms) in the census. This was done by matching operations who reported in the Area Frame June 2002 Agricultural Survey to their census report and comparing their answers. The information on the June Agricultural Survey was assumed to be correct, since it was collected in person by trained enumerators, while the census data were obtained in most cases through a self-administered mail form. Misclassification estimates for 2002 were generated based on cases where the census report was classified differently than the matching June Agricultural Survey report. The estimated misclassification rate was small but it was clear that, in some cases, the assumption of the June Agricultural Survey response being correct was not justified. Since the 2002 misclassification estimates were not used to adjust published census estimates, a different approach was taken for the classification error study in 2007. For 2007, the focus was on understanding why operations reported differently in the June Agricultural Survey than they did on the census, rather than on estimating misclassification rates. Census records were matched to operations’ reports from the 2007 June Agricultural Survey, but neither report was assumed to be “the truth.” As in 2002, this study targeted operations classified as farms in one case and non-farms in the other. In addition, it focused on operations who reported total acres operated that differed by more than 25 percent between June and the census. Instead of assuming one source was correct, these operations were reinterviewed, shown their June Agricultural Survey and census questionnaires, and asked to resolve and explain the discrepancies. In addition, operators were asked general questions related to suspected problems in reporting their acreage. The reinterviews uncovered several different sources of errors in reporting. These occurred in both the June Agricultural Survey and the census, with the majority of errors in the June Agricultural Survey. Errors were related to respondents, enumerators and National Agricultural Statistics Service procedures and show that a multi-part solution is needed to address them.