Topography, borders, and trade across Europe
利用欧洲河流网络和贸易路线崎岖度的新数据，结合结构引力模型，区分历史和当代贸易成本，发现地形解释了非接壤国家间的大部分贸易成本，且山脉的负面影响大于河流的正面影响。
We create a novel data set on the European river network and for the ruggedness of trade routes between European countries and integrate these new indicators into recently developed structural gravity models. Moreover, we propose a new approach how to differentiate between contemporaneous and historical trade costs. Applying two-stage structural gravity estimations, we assess the impact of topography on trade by combining worldwide, European, and domestic trade data. While border effect estimates remain largely robust, a main part of the historical and contemporaneous trade costs usually attributed to non-contiguity can be accounted for by topography. Finally, counterfactual simulations suggest that positive effects of rivers on trade are less important than negative effects of mountains.