Nonsampling Error: Despite efforts made in all phases of collection, processing, and tabulation to minimize errors, the survey is subject to non-sampling errors such as the inability to obtain data for every variable for all units, inaccuracies in classification, mistakes in keying and coding, and coverage errors.
Overall Unit Response Rate: The overall unit response rate is calculated as follows:
|Overall Unit Response Rate=||Number of units who reported all key variables for at least one function||X 100|
|Number of units in the eligible universe|
Total Quantity Reponse Rate: The total quantity response rate is calculated as follows:
|TQRR for tax category=||Sum of response data for tax category + Sum of equivalent quality-to-reported tax category||X 100|
|Sum of all data for tax category|
Tax codes with their corresponding description and TQRR are available in the Annual State Tax Collection Survey Methodology.