Marginal refers to the additional per unit cost, benefit, or other variable. For example, if you were to reduce pollution by one additional percentage point, the cost or benefit of this additional point would be referred to as the Marginal cost or benefit. In Market Economics, we refer to the most efficient production and price point as the point where MR=MC (Marginal Revenues equals Marginal Costs). This concept is similar for Environmental Economics. Economists always try to find the point where trade-offs are most efficient and this is referred to as the Equimarginal Principal. It is important not to confuse this with equiproportionate which is not always the most efficient point. What is the difference between both concepts? How would you use the equimarginal principle if you wanted to perform a benefit-cost analysis for the reduction of emissions? (100 words minimum)