The history of environmental economics is interwined with other histories and movements. These include (1) humanitys thinking about its relationship to Nature; (2) a redefinition of economics from the study of material welfare to the study of tradeoffs, including tradeoffs between developing resources and preserving them; (3) rising consumer movements and a shift in economic focus from the producer to the consumer, which in turn facilitiated a shift from thinking about the exploitation of resources to the enjoyment of preserved landscapes; (4) developments in economic theories of externalities and public goods; and (5) the increasing involvement of economics in government policy, from agricultural and resource economics to planning government spending and regulation.