Railroad deregulation increased cost savings from the cap-and-trade scheme by enabling Mid-Western electric utilities to reduce their S02 emissions by increasing their use of low-sulphur coal from Wyoming. Most legislative proposals to price GHG emissions, both in the United States and in other countries, have opted for cap-and-trade schemes over a tax. A major reason for this preference is that cap-and-trade facilitates building political support through grandfathering (i.e., giving permits to exiting emitters for free), which may be less transparent than recycling the revenues from a tax and more politically sustainable (subsidies have to be renewed regularly).