Methodology for Handling Missing Values In TANKAN

The "Short-term Economic Survey of All Enterprises in Japan" (Tankan) is a sample survey that contains both judgment questions and quantitative items. For the latter, we use a standard stratified sampling procedure, producing an estimate of the population total of each individual stratum. If missing values occur in a stratum, the estimated total for the population of that stratum is obtained by weighting the sum of respondents' values, where the weight used is the ratio of the stratum population to the number of respondents. This method is equivalent to estimating the total for the stratum population by filling in missing values with the stratum mean. However, in Tankan survey, the variance within each stratum is comparatively large, so that we must consider the possibility of large deviations between the stratum mean and the true values of nonrespondents. In light of such problems, this paper conducts experimental simulations in order to discover the most appropriate method for handling missing values in Tankan.