<P> Although marginal abatement costs can be negative, such as when the low carbon option is cheaper than the business - as - usual option, MACs often rise steeply as more pollution is reduced . </P> <P> Marginal abatement costs are typically used on a marginal abatement cost curve (MACC) or MAC curve, which shows the marginal cost of additional reductions in pollution . </P> <P> Carbon traders use MAC curves to derive the supply function for modelling carbon price fundamentals . Power companies may employ MAC curves to guide their decisions about long - term capital investment strategies to select among a variety of efficiency and generation options . Economists have used MAC curves to explain the economics of interregional carbon trading . Policy - makers use MAC curves as merit order curves, to analyze how much abatement can be done in an economy at what cost, and where policy should be directed to achieve the emission reductions . </P> <P> However, MAC curves should not be used as abatement supply curves (or merit order curves) to decide which measures to implement in order to achieve a given emission - reduction target . Indeed, the options they list would take decades to implement, and it may be optimal to implement expensive but high - potential measures before introducing cheaper measures . </P>

What is the formula for marginal cost of pollution abatement