When correcting for negative externalities, Diagon Mountain uses a Carbon Tax. A Carbon Tax is most effective for this because it provides an incentive for people to quit polluting. It also has a neutral revenue that isn't always fluctuating and the reinvestments also help the lower income families. The subsidies from this tax will also encourage positive externalities, such as education. Finally, and one of the most important reasons for Diagon, the carbon tax doesn't create a need for a new market. This tax also goes towards a fund that will provide our environmental clean up team (includes inmates and others who volunteer).