Islands in Trade: Disentangling Distance from Border Effects [Dataset]

Trade between regions separated by a sea border is affected by specific transport costs that have not been considered by the border effects literature. Among these are the existence of a time barrier, the need to combine different transport modes, or to pay fees and taxes for the use of public infrastructures such as ports and airports. The empirical strategy used to estimate the “island effect” proceeds in two steps: first an augmented gravity model is estimated for mainland and island regions; then a Blinder–Oaxaca decomposition is applied to the gravity estimation results in order to disentangle the distance and border effects for those regions. Results show that island regions are at a substantial disadvantage compared to continental regions, which is due to the higher and non-linear effect of distance coefficients.隔海分界的区域间贸易，受到边境效应相关研究文献尚未纳入考量的特定运输成本影响。此类成本包括时间壁垒的存在、需组合多种运输方式，或是为使用港口、机场等公共基础设施缴纳费用与税费。本次研究用于估算“岛屿效应（island effect）”的实证策略分为两步：首先针对大陆与岛屿区域构建拓展引力模型（augmented gravity model）并完成估算；随后将布林德-奥瓦卡分解（Blinder–Oaxaca decomposition）应用于引力模型的估算结果，以拆解此类区域的距离效应与边境效应。研究结果显示，与大陆区域相比，岛屿区域处于显著竞争劣势，该现象源于距离系数所产生的更强且非线性的影响。