My dissertation follows a coherent theme on three important and interesting issues for the Korean labor market as follows: Chapter 1 using data from the 2008 Panel Survey of Employment for the Disabled (PSED) investigates gender wage differentials among the disabled. The selectivity corrected decomposition framework is employed to examine what factors - endowments, discrimination, and selectivity - account for the wage gap. The main results are as follows: (1) the gender wage gap among the disabled is sizable: (2) the wage gap is significantly attributable to discrimination: (3) the endowments factor plays an important role in explaining gender wage differentials, as well: and (4) the presence of selection effects raises the observed wage g...