Nonsampling Error: All aspects of the survey collections are subject to nonsampling errors. These errors are due to mistakes that the respondent may have made, errors due to not receiving a returned questionnaire, or errors due to various processing issues, such as keying or classification. Such errors are mitigated by editing the data using prior quarter data or data from four quarters prior. Errors of nonresponse are mitigated by imputing for units that did not supply complete information or by weight calibration.
Response Rate: The Total Quantity Response Rates (TQRR) are given in Table 1a. TQRRs represent the percentage of the final estimate for a given variable that resulted from survey respondents. For the first quarter of 2012, five state governments did not report data and had to be imputed. These units are denoted in Table 3.