Baumgärtner and Quaas (2010a) are not clear where to situate sustainability economics: ecological economics research that does not focus on economic efficiency is not sustainability economics (p. 449), sustainability economics is a “related academic field” (p. 447) to ecological
economics, it is at the “intersection between ecological economics and resource and environmental economics” (p. 449), and “sustainability economics reestablishes the focus on the original idea of ecological economics” (Baumgärtner and Quaas, 2010b p. 2056).