WRI completed a major national economic analysis of agricultural sustainability in the United States in 1995. This study applied an NRA framework to analyze the economic and environmental impacts of alternative policies and production systems (Faeth, 1995). After compiling agronomic data from experiments, field trials, and producer records for alternative production systems in 10 regions of the United States, WRI evaluated these alternative systems, as well as the predominant systems for a given region, using a biophysical soil and crop model to determine soil erosion rates, long-term crop yields, nutrient loss, potential groundwater contamination from nitrates, and soil carbon sequestration. This information, together with financial and energy analysis and economic valuation of environmental impacts, makes the database supporting this project the single most complete collection of information yet available on "sustainable" production systems.
The economic model that resulted from the WRI study is the most comprehensive and empirically based policy tool yet developed for analysis of agricultural sustainability in the United States. To date, no national economic model has used such extensive information on alternative production systems, the environmental impact of predominant and alternative farming systems, or the economic value of natural resource impacts.
The research plan involved four steps: