Individual Growth in Self-Esteem, Bicultural Acceptance, Acculturative Stress, and Perceived Social Support Among Migrant-Background Youth in the Republic of Korea: A Multilevel Analysis of the Multicultural Adolescents Panel Study

The long-term inclusion of migrant-background youth can be framed, following the social-sustainability literature, as part of the social pillar of sustainability and of the Sustainable Development Goals on inclusive quality education (SDG 4) and reduced inequalities (SDG 10), yet the relational resources surrounding these young people have rarely been modelled at the individual level over more than a few years. This theory-guided descriptive study fits multilevel linear growth models to the 12 released waves (waves 1–10, 12, and 14; 2011–2024) of the first-cohort Multicultural Adolescents Panel Study of the Korean National Youth Policy Institute, following 1635 children of multicultural families from the fourth grade of elementary school in 2011, of whom 892 (54.6%) provided a valid composite at the final released wave; model-specific person-wave observations range from 6593 to 12,237. Six constructs are modelled as seven measurement series, because the self-esteem instrument was replaced in 2017 with no overlap wave; each series is analysed strictly within its own window: perceived peer support, teacher support, and acculturative stress from late elementary school to the final year of middle school (2011–2016); bicultural acceptance and family support from late elementary school to the final year of high school (2011–2019); and self-esteem as two separate series (2011–2016; 2017–2024). Across late elementary and middle school, perceived peer and teacher support rose—peer support fastest, with growth concentrated before the middle-school years and a reversal in the final middle-school year—while acculturative stress declined. Family support, observed through the end of high school, showed no robust directional change, and an equivalence test bounds any change below the magnitude of the acculturative-stress decline, the smallest trend interpreted substantively. Individuals differed reliably in their rates of change on every construct, and bivariate latent growth models show that those rates covaried within persons: young people with larger estimated gains in school-based support also tended to show larger gains in self-esteem and larger decreases in acculturative stress. The between-person spread of perceived school-based support narrowed across waves, although regression to the mean cautions against a strong compensatory reading. The direction of every trend was unchanged under person fixed effects and inverse-probability-of-retention weighting, and re-estimation from the item subset common to all waves yielded larger, not smaller, school-based support increases; a reliability audit established that the post-2017 self-esteem instrument requires reverse-scoring of its four negatively worded items; under the released, unreversed scoring, the resulting composite has effectively no internal consistency. The design is observational and no causal inference is warranted, but the results give an individual-level baseline, bounded by each construct’s measurement window, for monitoring the relational resources of migrant-background youth as a candidate social-sustainability indicator under SDG 4 and SDG 10, a possible application rather than a validated indicator framework.