미시 모의실험 모형을 통한 입원 진료비 분포 전망 = A Microsimulation Approach to Projecting the Distribution of Inpatient Medical Expenditures

다국어 초록 (Multilingual Abstract)

Health expenditure is a critical input for assessing the long-term financial sustainability of the National Health Insurance (NHI) system in South Korea. However, conventional fiscal projection models typically rely on point estimates and thus fail to capture distributional heterogeneity. This study develops a micro-simulation model using 2012–2017 Korea Health Panel Survey data to project the distribution of inpatient medical expenditures through 2072. The simulation framework draws on Sweden’s SESIM model and relevant domestic research. Inpatient expenditures are modeled using a three-class finite mixture model that distinguishes among non-users, low-cost users, and high-cost users of inpatient services. The projections show a steady rise in inpatient expenditures from the baseline period, with growth stabilizing around 2050—likely due to demographic shifts, including a future decline in the elderly population. At the same time, the projected expenditure distribution indicates increases in both hospitalization rates and the proportion of high-cost users. Panel quantile regression results further demonstrate that socioeconomic characteristics—such as age, disability status, and household income—exert heterogeneous effects across the expenditure distribution. These findings suggest that, beyond demographic change, intensifying medical service use among survivors may play an increasingly important role in shaping the future distribution of healthcare expenditures.