Another relevant idea comes from the literature on Jevons Paradox. There is the abbreviated reference on the AGS site under References/Reading materials. But there is also "The Myth of Resource Efficiency: The Jevons Paradox" by Polimeni, J.M. et al. 2008, Earthscan. If you have this reference or get it, go to page 21-22 under a section titled "what is output?" There is a discussion of utility and externalities that seem relevant to LCA. There are other (obviously) relevant ideas throughout this reference but it seems that the concept of who decides (and how you decide) what goes in the numerator is an important idea. In Jevons original work (1800s), he states that utility is not an inherent value -- meaning that the utility of something changes depending on how much you currently have of it as well as context (e.g., how useful it is now compared to some other time). In this context, it would be interesting to discuss whether and how LCA might change over time -- should it or shouldn't it? Are the elements that go into LCA fixed (like a standard set of indicators or criteria)? If not, when do they change? Who decides? If so, why and who decides? Just some ideas to ponder. Thanks for your efforts!