The labor force participation (LFP) rate in Korea has leveled off since 1991. There are three phenomena which are widely believed to be associated with the plateau in Korean LFP: a rise in educational attainment among men and women in their twenties, a low LFP rate among married women with young children, and babyboomers’ early retirement. To see how the trends in the LFP rate, educational attainment, and marital status are inter-related, I investigate changes in LFP rates and the related socioeconomic outcomes of men and women by birth cohort using Economic Activity Survey data from 1986 to 2012. I also conduct a series of shift-share analyses that decompose changes in LFP into composition and within-group effects, with groups defined by educational attainment and marital status. I find that for men in their late twenties, changes in their LFP rate are mostly explained by changes in their educational attainment. For women in their late twenties, however, changes in their LFP rate are mostly explained by changes in their marital status. For men and women aged 30 or older, changes in their educational attainment and marital status did not contribute much to changes in their LFP rate. These analyses imply that policies that impact educational composition of the population, such as providing incentives to hire high school graduates rather than college graduates, may have more effects on men than women. To raise LFP rate and employment-population ratio as government intended, policies should be implemented with more focus on women.