Many new and proposed emissions trading systems involve multiple countries and regions. The introduction of interregional trading raises questions about how flexible state- or national-level authorities should be in allowing individual firms to trade with firms or authorities in other states or...

Irrigation can have a significant negative impact on the environment. Policies available to regulators to reduce the impact of irrigation include externality taxes and levies. In 2002 the Victorian Government introduced a system of salinity levies in the irrigation regions of Sunraysia, northern...