Carnegie Mellon University

About The EIO-LCA Method

The Economic Input-Output Life Cycle Assessment (EIO-LCA) method estimates the materials and energy resources required for, and the environmental emissions resulting from, activities in our economy.  It is one technique for performing a life cycle assessment, an evaluation of the environmental impacts of a product or process over its entire life cycle.  The method uses information about industry transactions - purchases of materials by one industry from other industries, and the information about direct environmental emissions of industries, to estimate the total emissions throughout the supply chain.  

This section of the website provides an overview of life cycle assessment (LCA), different approaches to LCA, the theory and mathematical method of the EIO-LCA approach, assumptions and uncertainty in the model, and limitations to the approach.  The information is only a brief overview, however, and is not intended to encompass all issues and nuances of the topics.  References are provided to resources with more detailed information and analyses.   

Economic Input-Output Life Cycle Assessment (EIO-LCA) is a method - a mathematically defined procedure using economic and environmental data to determine the effect of changing the output of a single sector.  The method can be applied to any economy defined by the transactions between sectors.  Each application of the method defines an EIO-LCA model.  Go to the Models page for more information about the various models available on

Also note that we published a "handbook" with RFF Press in 2006 to help explain the EIO-LCA method and to show how to use it with examples:

Hendrickson, C. T., Lave, L. B., and Matthews, H. S. Environmental Life Cycle Assessment of Goods and Services: An Input-Output Approach, Resources for the Future Press. 

You can order it from RFF with this PDF invoice or buy the hardback or paperback edition from Scott Matthews CMU