Theory of materials and energy flow analysis in ecology and economics

Materials and energy flow analysis (MEFA) has been widely utilized in ecology and economics, occupying unique positions in both disciplines. The various approaches to materials and energy flow analysis in ecology are reviewed, the focus being on the linear network system introduced from input–output economics. After its introduction in the early 1970s, the calculus and system definition for materials and energy flow analysis have been diversified, causing problems in comparing the results of different studies. This paper uses a materials and energy flow analysis framework that is a generalization of the major approaches in ecology and economics to illuminate the differences and similarities between the approaches on the basis of a set of consistent principles. The analysis often shows that seemingly different calculus and interpretations employed by different approaches eventually lead to the same outcome. Some issues of interpretations that conflict or require cautious interpretation are further elaborated. A numerical example is presented to test the generalized framework, applying major analytical tools developed by other approaches. Finally, some parallels, convergents, and divergents of the perspectives of ecology and economics and their implications for endogenized resources economy are discussed as they are reflected in the materials and energy flow analysis frameworks.