5. Mono-metrical (or single dimensional) vs multicriteria evaluation

Single-dimensional approaches

Approaches based on the evaluation on a single common unit, be it monetary, physical or other, assume that there is only one language of valuation.

If we are able to have a single measure for sustainability, then it will be very straightforward to choose among different alternatives in conflicts.

Single-dimensional approaches seek to derive a common and single unit to measure sustainability. These units can be based either on physical units (such as quantity of materials or energy) or on value units (monetary).

Cost-benefit analysis for instance is based on the monetary valuation of all impacts of a given project, adopting economic value as the single language of valuation.

Approaches based in one common physical indicator such as the ecological footprint, energy balances or material flow analysis are other examples of single-dimensional approaches to sustainability assessment.

Those approaches based on one single common unit bring all information to a single of valuation. Multi-criteria approaches, on the other side, try to accommodate the plurality of values and perspectives regarding environmental issues, and to account separately for the different forms of capital.

(lien grain : 4 capitals)

Multicriteria evaluation

Plurality of perspectives

Once we accept the plurality of valuation languages, the units of measure we use to characterise the situation or some of its dimensions are different, non-commensurable. This means we cannot adopt a single and unique measuring rod to evaluate simultaneously economic assets, biophysical elements of ecosystems, livelihoods, happiness, well-being, cultural values, etc. Comparisons among these dimensions have a limited meaning and are only valid within a particular decision context.

It is then necessary to organize the assessment process with method in an informed way.  Multi-criteria platforms are useful, to conduct those assessments.

Comparison of methods

Paula Antunes suggests a table for comparing methods, inspired from Vatn, 2008:

This is the end of the area: introduction to sustainability assessment. You can procede to next area "Single dimensional approaches" or to "Multi-Criteria Assessment".