Sex ratio at birth remains highly skewed in Asian countries due to son preference. In South Korea, however, it has declined to the natural ratio. In this paper, we investigate whether son preference has disappeared in Korea by analyzing parents' time and monetary inputs by the sex of their child. We exploit randomness of the first child's sex to overcome potential bias from endogenous fertility decisions. Our findings show that mothers are more likely to work after having a girl, girls spend twice as much time as boys in housework activities, and parents spend more on private education for boys.

This paper estimates an education production function using data on the College Scholastic Ability Test score and high school characteristics from Seoul, Korea, where, on entering high school, students are randomly assigned to schools within each school district. We derive a school production function by aggregating the individuals' potential outcomes under the random assignment and no cohort effect assumption. We find that the school production function coefficients differ between districts and that the single-sex school effect estimate is much larger than that found in previous studies.