Econ Papers Daily / 期刊论文
不对称交易成本与古希腊城邦
Asymmetric trading costs and ancient Greek cities
摘要
Asymmetric trading costs arise when shipping times from point i to point j differ from shipping from point j to i. We show that such asymmetric trading costs predict distinct patterns of location in a class of models using Anderson-Dixit-Stiglitz preferences, where advantage in import market access (or potential) is more beneficial than that in export market access. We bring this prediction to the data, as well as additional ones along the lines of a number of propositions, while also controlling for local micro-geographic characteristics and using data on the location and sizes of cities in ancient Greece. Prevailing winds create an environment of asymmetric and seasonally varying trading costs in ancient Greece. We find that trade potential is strongly associated with the location and size of poleis. The model’s directional prediction is supported when trade potential is measured using the left and right eigenvector centralities implied by the model: import-oriented centrality has a larger coefficient than export-oriented centrality. The result is less robust for alternative reduced-form measures. Using 2SLS methods for population-weighted market access, we find significant differences between export and import market access, with the former often more important than the latter. These findings show that directional asymmetries in trading costs matter for urbanization, while also suggesting that their empirical implications depend on how directional access is measured.
中文摘要
当从i地到j地的运输时间不同于从j地到i地的运输时间时，便会产生非对称贸易成本。我们表明，在一类采用Anderson-Dixit-Stiglitz偏好的模型中，这种非对称贸易成本会预测出不同的区位模式，其中进口市场准入（或潜力）方面的优势比出口市场准入方面的优势更有益。我们将这一预测以及沿着若干命题得出的其他预测带入数据检验，同时控制地方微观地理特征，并使用古希腊城市位置和规模的数据。盛行风在古希腊营造出一种非对称且随季节变化的贸易成本环境。我们发现，贸易潜力与城邦的位置和规模密切相关。当使用模型所隐含的左、右特征向量中心性来衡量贸易潜力时，模型的方向性预测得到支持：进口导向中心性的系数大于出口导向中心性的系数。对于替代性的简约式衡量指标，这一结果稳健性较低。使用2SLS方法处理人口加权市场准入时，我们发现出口市场准入与进口市场准入之间存在显著差异，前者往往比后者更重要。这些发现表明，贸易成本中的方向性非对称对城市化具有重要意义，同时也表明其经验含义取决于方向性准入如何被衡量。