Maritime Freight Costs in China's Soybean Import Prices: Evidence from Brazil and the United States

China is the world's largest soybean importer, while its domestic production remains substantially below domestic utilization. This dependence on geographically distant suppliers makes maritime transportation relevant to the delivered value of China's soybean imports. This study aims to assess the extent to which estimated maritime transport and insurance cost margins contribute to China's cost, insurance, and freight (CIF) soybean import unit values from Brazil and the United States, and how variation in these costs relates to the relative delivered-price competitiveness of the two supply routes between January 2022 and May 2025. Monthly bilateral trade data are used to construct country-specific margins between CIF import unit values and free on board (FOB) export unit values. Two main ordinary least squares models are estimated, together with an additional United States model that includes a Panama Canal restriction period variable. Statistical inference is based on Newey-West heteroskedasticity- and autocorrelation-consistent standard errors. The estimated margins represent, on average, approximately 12.0% of the CIF unit value for imports from Brazil and 10.7% for imports from the United States, while the United States margin shows greater monthly variation. Although the higher Brazilian margin narrows Brazil' s delivered-price advantage over the United States, it does not eliminate it, while the greater variation in the United States margin indicates less stable transport-cost conditions on that route. Monthly changes in Brent crude oil prices and the U.S. dollar/Chinese yuan exchange rate are not statistically significant in either main model. The Global Geopolitical Risk Index has a significant negative association only in the United States model, while the Panama Canal restriction coefficient is positive but statistically insignificant. The findings indicate statistical associations rather than causal effects.