Multistage Process-Based Make-Use System

The System of National Accounts (United Nations 1968, 1993) is a useful tool for measuring not only the effects of technological changes, input composition changes, product-mix changes, and consumption shifts as fundamental structural elements (e.g., Afrasiabi and Casler 1991; Rose and Casler 1996; Dietzenbacher and Los 1998, 2000 for the exposition of structural change analyses) but also the efficiency indices consistent with neoclassical economic theory such as total factor productivity growth and labor productivity growth (e.g., ten Raa 1994,1995a; ten Raa and Mohnen 1994).

1

The key to the system's utility rests on the structural elements provided.

In analyzing environmental consequences of productive systems, the emphasis has been generally on microscopic level, where process-based Life Cycle Assessment (LCA) may be a representative tool (Guinée et al. 2002). The analysis measures physical energy and material requirements for the processes of the product system in question

inside

a well-defined system boundary and provides very detailed inventories of environmental emissions and resources use. Hybrid Life Cycle Assessment model, where the standard input-output model and the process-LCA model are combined, additionally enables us to cover the indirect intermediate inputs

outside

the process-based system boundary (e.g., Moriguchi et al. 1993; Suh 2004; Suh et al. 2004). In this case, the concept of a sector outside the system boundary no longer relates to a process but to a standard commodity or an industry.