Analysis of import demand elasticity for crustacean aquatic products in China

China’s crustacean imports expanded rapidly during 2013–2023 while becoming increasingly concentrated among a few major suppliers, raising exposure to origin-specific shocks. Using monthly China import value–quantity data for HS 0306, we document import growth and concentration dynamics (market shares, CR4/CR8, and HHI) and estimate an origin-differentiated Linear Approximate Almost Ideal Demand System (LA/AIDS) via SUR under standard demand-theory restrictions (adding-up, homogeneity, and symmetry). Import volume increased from 0.089 million tons in 2013 to 1.24 million tons in 2023, and import value rose from USD 0.52 billion to USD 9.57 billion. Market concentration intensified, with the HHI increasing from 1,623 to 3,350 over 2013–2023. The elasticity estimates suggest that concentration risk depends not only on current shares but also on how incremental demand growth is allocated across origins. Ecuador exhibits a robustly above-unity expenditure elasticity (approximately 1.9), implying growth-driven dependence on this dominant supplier. India’s expenditure elasticity is above unity in the baseline specification (about 1.26) but is more sensitive to alternative samples and supplier definitions. Russia and Argentina show significantly negative own-price elasticities, indicating price-sensitive import demand. In contrast, positive own-price responses for Canada and the United States in the aggregate HS0306 system should be interpreted cautiously because unit import values may embed quality/composition shifts and curvature is not imposed in estimation; product-type subsamples provide evidence consistent with aggregation/quality effects. Compensated cross-price elasticities reveal that substitution capacity is uneven and concentrated in a limited set of strong, asymmetric corridors—most notably Ecuador–Argentina, India–Canada/United States, and Russia–New Zealand/United States—indicating where China can most plausibly reallocate sourcing under origin-specific price shocks. Robustness checks (alternative price-index construction, winsorization, excluding the COVID disruption period, alternative major-supplier definitions, and shrimp/crab subsamples) support the main qualitative patterns. Overall, rising concentration combined with corridor-specific substitution capacity implies origin-specific resilience risks and motivates targeted diversification and contingency sourcing strategies guided by empirically identified substitute routes.