Population Aging and GVC Upgrading in China: Firm-Level Associations and Provincial Patterns

China is aging rapidly as manufacturing firms seek higher positions in global value chains (GVCs). Using firm-level data for 2000–2013, we find a negative association between the provincial old-age dependency ratio and firm GVC upgrading under year fixed effects. The coefficient is economically non-trivial but does not reach conventional significance under wild-cluster bootstrap inference. Firm fixed effects attenuate it to near zero, pointing to a between-firm (compositional) pattern rather than weaker upgrading among continuing firms. Only human capital shows a detectable indirect association; saving, R&D, and inward FDI do not. A provincial panel for 2014–2023 shows no robust negative link between aging and log export technological complexity. Because the two analyses differ in unit, period, outcome, and design, the contrast is a descriptive divergence, not an identified paradox or a test of policy compensation. The within-versus-composition distinction is relevant for other economies aging before affluence.