%0 Journal Article %T Environmental Efficiency and Urban Ecology %A Ching-Yu Chen %A Jwu-Rong Lin %J Theoretical Economics Letters %P 422-446 %@ 2162-2086 %D 2021 %I Scientific Research Publishing %R 10.4236/tel.2021.113028 %X Evaluating organizational efficiency involves measuring outcomes, such as revenues, value of goods and services produced, productivity, etc. However, a sustainable environment requires not only economic outcomes but also good quality of life in an area. Therefore, this research proposes a balanced assessment to evaluate environmental efficiency from the perspectives of urban ecology. We first adopted the bad output data envelopment analysis to evaluate the efficiency of a metropolitan area followed by a biotope area factor to assess the ecological effectiveness of an area. Next, a censored regression model evaluates the relationship between environmental efficiency and biotope area factor. The empirical studies were conducted in Taichung, Taiwan. Empirical results suggest that typical efficiency evaluation of a metropolitan area is significantly overrated because it excludes external diseconomies such as CO2 emissions which have a profound impact on the environment. The regression results indicate that environmental efficiency and Taiwan biotope area factor are complementary and can be improved simultaneously while CO2 emission reduction is at present. We also show that current utilization of area for non-agriculture and human activities poses a negative impact on Taiwan biotope area factor. %K Bad Output Data Envelopment Analysis %K Biotope Area Factor %K External Diseconomies %K Technical Efficiency %K CO2 Emissions %K Sustainability %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=109640