We used data from the fourth wave of the Korean Welfare Panel Study (KWPS),
which contained information on 6,207 households. The KWPS is a nationwide
longitudinal survey of a representative sample of the Korean population. The
supplemental survey of KWPS has different themes. The fourth dataset contains
information on families’ socio-economic characteristics and expenditures on private
tutoring in the main survey, and middle school students’ academic achievement and
behaviors of their parents in the supplemental survey (The Korea Institute for Health
and Social Affairs & Seoul National University, 2009).