Youth Employment Dynamics in Korea’s Blue Economy: Employment Adjustment and Labor Turnover Across Industries

The social sustainability of blue economy development depends not only on job creation but also on younger workers’ access to marine industries and the durability of their employment pathways. Using quarterly establishment microdata from Korea’s Marine and Fisheries Employment Trend Survey for 2021Q1–2026Q1, this study examines youth employment adjustment and labor turnover across nine industries. The main sample contains 25,273 consecutive-quarter transitions from 4727 establishments. Youth combines the survey’s “20s or below” and 30–34 age bands. In the adjusted survey-weighted model, the youth-adjustment coefficient is 0.124 (SE = 0.018), compared with a lagged economy-wide youth employment share of 0.132; a 10,000-replication establishment-cluster bootstrap gives p = 0.693. However, stricter establishment-level proportionality is rejected (p = 0.012), indicating that aggregate benchmark consistency does not imply uniform establishment behavior. Industry-level adjustment and expansion–contraction differences do not survive Holm correction. In the full cross-sectional flow sample, youth accession and separation rates are 4.64% and 4.07%, versus 2.63% and 2.64% for non-youth workers. Holm-adjusted separation gaps remain significant in marine leisure and tourism and marine-related services. The findings distinguish aggregate compositional regularity from establishment-level heterogeneity and industry-specific turnover processes.