Reconciling four national statistical sources for aggregate supply–demand assessment: a framework applied to South Korea

Construction aggregates, the most extracted solid materials, are typically assessed from a single, unvalidated statistical source, rarely disaggregated by commodity or region. We place four Korean sources—an extraction register (AGRIS), ready-mixed concrete (RMC) shipments (KRMCIA), cement shipments, and procurement microdata (KONEPS)—on a common footing through the concrete batch ratio, 2018–2024. The central result is compositional: the relative sand-to-gravel sufficiency ratio R is 0.59 (Monte Carlo 5–95% interval 0.43–0.86; P( R < 1) = 99.2% under the stated input distributions), robust under commodity-neutral reporting and demand-scope assumptions across the stated fine-aggregate-ratio sensitivity range. The observed AGRIS sand share is 12.6 percentage points below the RMC mix-design fine-aggregate ratio. The corresponding compositional gap for total aggregate demand is not identified because the composition of non-RMC demand is unobserved. Levels are reported only as indices: national supply averages 81.3% of RMC-implied demand. Spatially, the recorded-supply gap is concentrated: by volume, Gyeonggi alone carries approximately 41% of the summed local recorded-supply gaps against RMC-implied demand, and at the proxy functional-region level the Daegu region is the most supply-constrained (lowest self-sufficiency ratio, SSR, 51.8%; sido-level SSR 0–136%). A rebuilt cross-validation anchor declines from 99.7% to 88.6%, indicating a widening discrepancy between KRMCIA-reported shipments and cement-implied RMC production under a time-constant RMC share of bulk cement shipments and use of the KONEPS public-procurement mix as a national proxy. The decline is not uniquely attributable to changing KRMCIA reporting coverage. The framework transfers to any jurisdiction holding independent supply- and demand-side series.