Urban sustainability assessment of Taiwan based on data envelopment analysis Wen-Chi Yang a,b , Yuh-Ming Lee a,n , Jin-Li Hu c a Institute of Natural Resources Management, National Taipei University, Taiwan 151 University Rd., San Shia District, New Taipei City 23741, Taiwan b Department of Diplomacy, National Chengchi University, Taiwan 64 ZhiNan Rd., Section 2, Wenshan District, Taipei City 11605, Taiwan c Institute of Business and Management, National ChiaoTung University, Taiwan 118 Chung Hsiao W. Rd., Section 1, Taipei City 10044, Taiwan article info Article history: Received 21 July 2014 Received in revised form 16 August 2015 Accepted 6 April 2016 Keywords: Undesirable outputs Window analysis Urban metabolism Aggregate efficiency Disaggregate efficiency abstract The rapid process of urbanization brings forth growing concerns about the sustainability of cities. This study adopts an extended urban metabolism framework to assess urban sustainability and utilizes a data envelopment analysis (DEA) model with undesirable outputs that takes pollutions into account in order to measure the aggregate urban input–output efficiency of Taiwan's 22 administrative regions. The model not only compares aggregate urban efficiency, but also identifies which input or output item should be adjusted and what the target values are. The results indicate that Taipei City and Lienchiang County are the most sustainable cities in Taiwan. This study also proposes several indices, categorized as resource efficiency and pollution efficiency. In terms of resource efficiency, the findings present that Taiwan needs to improve its electricity and water efficiencies the most. With regard to pollution efficiency, garbage efficiency performs the best. Finally, industrial structure has a strong influence on resource efficiency and pollution efficiency. & 2016 Elsevier Ltd. All rights reserved. Contents 1. Introduction ........................................................................................................ 341 2. Concepts and methods ............................................................................................... 342 2.1. Urban metabolism and its application to urban sustainability assessment ................................................ 342 2.2. Data envelopment analysis and its application to undesirable outputs ................................................... 343 2.3. Window analysis .............................................................................................. 343 3. Framework and data ................................................................................................. 344 3.1. Framework and indicator selection................................................................................ 344 3.2. Data and indicators ............................................................................................ 344 3.3. Aggregate and disaggregate efficiencies ............................................................................ 344 4. Empirical results .................................................................................................... 345 4.1. Aggregate urban input–output efficiency of Taiwan's 22 administrative regions ............................................ 345 4.2. Resource efficiency ............................................................................................ 347 4.3. Pollution efficiency ............................................................................................ 347 5. Discussion ......................................................................................................... 348 5.1. Aggregate urban efficiency and industrial structure .................................................................. 348 5.2. Resource efficiency, pollution efficiency, and industrial structure........................................................ 348 6. Conclusion ......................................................................................................... 349 Acknowledgments ....................................................................................................... 350 Appendix A. ........................................................................................................... 350 References ............................................................................................................. 352 Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/rser Renewable and Sustainable Energy Reviews http://dx.doi.org/10.1016/j.rser.2016.04.015 1364-0321/& 2016 Elsevier Ltd. All rights reserved. n Corresponding author. Tel./fax: þ886 26721784. E-mail addresses: pinkwinnie330@gmail.com (W.-C. Yang), yml@mail.ntpu.edu.tw (Y.-M. Lee), jinlihu@yahoo.com, jinlihu@gmail.com (J.-L. Hu). Renewable and Sustainable Energy Reviews 61 (2016) 341–353