扩展边境效应模型的鲁棒性检验研究——基于中美港口航运贸易数据

Study on Robustness Checks of the Extended Border Effect Model for Shipping Trade

在边境效应引力模型理论和实证研究的基础上,构建考虑贸易方向、适用于港口进出口航运贸易的边境效应引力模型的扩展模型,基于2005～2009年中美港口数据采用六种方法对构建的扩展模型进行鲁棒性检验和非线性检验。结果发现:构建的扩展模型是一个较优的模型,进出口港口的经济总量、吞吐量和两个港口之间的经济距离是影响双边航运贸易量的关键因素;距离的计算方法会造成边境效应的高估或低估;国家的有形边境会造成无形的贸易障碍,并在进出口两个方向上对贸易的阻碍程度是不对称的,但都显著存在。

Based on the Gravity Model, a new extended border effect model is built to consider the direction of international trade for shipping industry. Robustness checks and non-linear checks are conducted by using China-US shipping trade data over the period of 2005-2009. The results indicate that the new extended border effect model considering the direction of international trade is well-established, and that the aggregate economic level, ports＇ handling capacity and the distance between the import port and the export port are of greater importance in deciding the final volume of bilateral shipping trade. It is also found that the border effects exist with significance and vary in two directions, and that the way of calculating the variable of distance can trigger great differences in border effects.