The Social Sciences Discussion Group (SSDG), convened under the auspices of the EPA Science Policy Council, was initiated to address issues related to the conduct of economic and other social science analyses at EPA. One of their efforts focused on improving the Agency's ability to conduct economic benefit analyses for regulatory cost-benefit or relative benefit assessments. The SSDG identified a need to 'improve the Agency's ability to quantify, and, where possible, monetize ecological benefits, including quality of life.' A workgroup representing all major EPA programs and environmental media was established to meet that charge. The workgroup began by surveying EPA offices for completed or ongoing analyses of ecological benefits to determine the current state of the practice within EPA. During this exercise, the workgroup identified the need for a common approach to analyzing ecological benefits and a better understanding of both the scientific and economic techniques used in these analyses. This document represents a joint effort of ecologists and economists. This document is intended to address the two needs identified above by (1) proposing a common framework for the economic analysis of ecological benefits and (2) discussing the elements of ecological risk assessment and economic benefit analysis.