Abstract

Port activity brings economic benefits to port cities but also generates negative environmental externalities. These negative externalities derived from pollutants represent a social cost for port cities and coastal areas close to ports, and include costs derived from damages to urban buildings, damage to vegetation and damage to the health of the local population. This raises the question of whether ports may have scope to reduce external costs and thereby improve air quality in port cities and/or increase their existing level of service. To address this, we estimate the environmental efficiency of 37 Spanish ports observed in 2016 for which data on inputs, outputs and local external environmental costs are available. Using Data Envelopment Analysis, we estimate a hybrid model with non-separable good and bad outputs. Undesirable output is measured for the first time by local external costs of air pollution instead of tons of pollutants released, which better reflects the differential damages caused by the individual pollutants. Two definitions of undesirable outputs are used: total local external costs and local external costs per capita. In both versions of the model, we find evidence of high levels of environmental inefficiency in Spanish ports, with over half of the ports found to be inefficient. We rank efficient ports using a super-efficiency version of the model with external costs per capita and identify ports which appear to be references for best practice.

摘要

港口活动给港口城市带来了经济效益，但也产生了负面的环境外部性。这些来自污染物的负外部性代表了港口城市和靠近港口的沿海地区的社会成本，包括城市建筑受损、植被受损和当地人口健康受损所带来的成本。这就提出了一个问题，即港口是否有空间降低外部成本，从而改善港口城市的空气质量和/或提高其现有的服务水平。为了解决这个问题，我们估计了 2016 年观察到的 37 个西班牙港口的环境效率，其中提供了有关投入、产出和当地外部环境成本的数据。使用数据包络分析，我们估计了一个具有不可分离的好输出和坏输出的混合模型。不良产出首次以当地大气污染的外部成本而非排放的污染物吨数来衡量，更好地反映了单个污染物造成的不同损害。使用了两个不良产出的定义：当地外部总成本和人均当地外部成本。在模型的两个版本中，我们发现西班牙港口的环境效率严重低下，超过一半的港口被发现效率低下。我们使用具有人均外部成本的模型的超效率版本对高效港口进行排名，并确定似乎是最佳实践参考的港口。使用了两个不良产出的定义：当地外部总成本和人均当地外部成本。在模型的两个版本中，我们发现西班牙港口的环境效率严重低下，超过一半的港口被发现效率低下。我们使用具有人均外部成本的模型的超效率版本对高效港口进行排名，并确定似乎是最佳实践参考的港口。使用了两个不良产出的定义：当地外部总成本和人均当地外部成本。在模型的两个版本中，我们发现西班牙港口的环境效率严重低下，超过一半的港口被发现效率低下。我们使用具有人均外部成本的模型的超效率版本对高效港口进行排名，并确定似乎是最佳实践参考的港口。