Input-Output Analysis (IOA) has recently been introduced to Life Cycle Assessment (LCA). In applying IOA to LCA studies, however, it is important to note that there are both advantages and disadvantages.
This paper aims to provide a better understanding of the advantages and disadvantages of adopting IOA in LCA, and introduces the methodology and principles of the Missing Inventory Estimation Tool (MIET) as one of the approaches to combine the strengths of process-specific LCA and IOA. Additionairy, we try to identify a number of possible errors in the use of IOA for LCA purposes, due to confusion between industry output and commodity, consumer’s price and producer’s price.
MIET utilises the 1996 US input-output table and various environmental statistics. It is based on an explicit distinction between commodity and industry output.
MIET is a self-contained, publicly available database which can be applied directly in LCA studies to estimate missing processes.
By adopting MILT results in existing, process-based, life-cycle inventory (LCI), LCA practitioners can fully utilise the process-specific information while expanding the system boundary.
MIET will be continuously updated to reflect both methodological developments and newly available data sources. For supporting information sec http:// wwwJeidenuniv.nl/cml/ssp/softwarc/miet.
The Missing Inventory Estimation Tool (MIET) was developed to combine process-specific life cycle inventory data with environmentally extended input-output analysis. The paper describes MIET as a publicly available database for estimating processes that are missing from an existing inventory. This can help an LCA include relevant activities beyond the processes for which detailed data have already been collected.
MIET uses the 1996 US input-output table together with environmental statistics. A key part of the method is to distinguish between industry output and commodity output, and between producer prices and consumer prices. These distinctions matter when translating economic data into environmental inventory estimates. The authors explain that input-output analysis can support broader system coverage, while also warning that its advantages and disadvantages need to be considered when applying it in LCA.
In practice, the estimate depends on matching the economic data to the inventory flow being completed. The paper highlights two distinctions that help avoid errors: a commodity is not the same as the output of an industry, and consumer prices are not the same as producer prices. MIET is intended to complement process-specific data by estimating gaps, so the resulting inventory can retain the detailed information already available while representing a wider system boundary.
