Dear Rone, Thank you for using the KOSIS website. 1 ~ 2. Basically we calculate the Gini coefficient or S80/S20 (the mean income of highest quintile/income of lowest quintile) according to the way the OECD recommends. We use equivalised disposable income, and we take the equivalence scale as the root of the size of household. That is the calculation of income distribution measures based on the numbers of people, rather than the numbers of households. On the other hand, two surveys respectively follow the same way based on their own survey results. 3. Meta data are not provided in English. Please refer to meta data in Korean on the following webpage. (http://meta.narastat.kr) 4. Self-employed persons (e.g. operators of small and microenterprises), especially those in the informal sector, may have their receipts and expenditures inextricably mixed up with those for the household, which makes reporting their income difficult. For these reasons, it has sometimes been argued that mixed income may not be the best measure of self-employment income in all instances. One alternative that has been proposed is to use “drawings” from the business.
Best regards, Statistics Korea