intensity of production, referring to the realm of production. The second pair, environmental improvement cost and its inverse, environmental cost-effectiveness, are defined from an environmental improvements measures point-of-view." The ratios may be applied to any unit comprising economic activities because such activities always relate to cost and value, "and having some physical substrate, always influence the environment." Furthermore, there are two different levels upon which to orchestrate the ratios: micro and macro. There are three different methods to determine eco-efficiency at the micro-level. First, incremental eco-efficiency, which "specifies the effects of the total value of a product system or sector and its total concomitant environmental effects." Second, an analysis method nicknamed win-win, which "gives a comparison between a historical reference situation and potentially new situations based on the use of new technologies." The win-win micro-method is limited because it cannot give a concrete answer on the question of whether it improves overall environmental performance. And the third is difference eco-efficiency, which is similar to the win-win variant, but removes all irrelevant alternatives to heighten potential for optimal technologies while comparing two alternatives. Now the macro-level is much less defined and has shown less accurate results. However, "the ultimate aim of eco-efficiency analysis is to help move micro-level decision making into macro-level optimality." The main goal in years to come is to create headline indicators to carry out macro-level analysis at a country/world scale. There are two life-cycle assessment (LCA)–based calculation systems on eco-efficiency: the analysis method of BASF, and the method of the eco-costs value ratio of the Delft University of Technology. Uses The reduction in ecological impacts translates into an increase in resource productivity, which in turn can create a competitive advantage. According to the WBCSD, critical aspects of eco-efficiency are: A reduction in the material intensity of goods or services; A reduction in the energy intensity of goods or services; Reduced dispersion of toxic materials; Improved recyclability; Maximum use of renewable resources; Greater durability of products; Increased service intensity of goods and services. Strategies that have been linked to eco-efficiency include "Factor 4" and "Factor 10", which call for specific reductions in resource use, "natural capitalism", which incorporates eco-efficiency as part of a broader strategy, and the "cradle-to-cradle" movement, which claims to go beyond eco-efficiency in abolishing the very idea of waste. According to Boulanger, all versions of eco-efficiency share four key characteristics: Confidence in technological innovation as