American-style capitalism, sans regulation, has earned its present bad rap. Even so, some market mechanisms do work quite well. Commodities pricing is discovered and costs kept low because markets are very efficient at making sure that metals, oil, food, etc. are moved to where the demand is the highest from where the supply is greatest. Similarly, a market in traded sulfur emissions imposed by the Clean Air Act has enabled fossil fuel plants to reduce sulfur dioxide emissions (the main source of acid rain) dramatically since the market’s inception.

Markets don’t work for everything, however. The sulfur dioxide emissions market works because the effects are not hyper-localized – farmers in Kansas and Iowa won’t notice the difference between the emissions from coal plants in Denver, Boulder, or Fort Collins. However, in the case of mercury emissions from coal plants, an emissions market would be a very, very bad idea. Coal-produced mercury precipitates out of the air in a plume immediately downwind of the emissions source, and so there’s no way to fairly balance the increased emissions of one coal plant with the lower emissions of another. In this case, all the increased mercury emissions would to is poison more mothers and children.

But because markets work so well for so many things, the creation of a cap-and-trade market for carbon dioxide (CO₂) makes a lot of sense. In a similar fashion to sulfur dioxide and unlike mercury emissions, CO₂ emissions mix well with the atmosphere and so trading emission credits between one source and another is viable. Continue reading →