What are the First and Second Laws of Thermodynamics? What is entropy and why is it relevant to economics? What does the economic system require as inputs? What does it create as outputs? What are the three constraints on the economic system according to entropy theory? What is input-output analysis? What are some of its limitations? What is the difference between a static and a dynamic input-output analysis? What is industrial ecology? Can one model accurately describe all flows in a system? What does the Brabant model attempt to model? What do we mean when we say that we should take an eclectic approach to studying environmental issues?