How do I aggregate at the stakeholder/impact category level for comparison purposes?

Question

Dear LCA community, 

In the course of a social hotspot analysis via PSILCA, I would like to compare not only the significance of social risk of sectors/processes, but also the aggregated social risk by impact category and/or stakeholder category within a process/sector. Since the number of indicators varies by impact and stakeholder category, a simple aggregation of, for example, medium risk hours would give the wrong impression. My first thought was to create arithmetic averages for the individual stakeholder groups and compare them.However, PSILCA uses an exponential scoring approach via the "Social Impact Weighting Method" and therefore this way would not be mathematically clean and also very high risk hours are "averaged out" (which contradicts the exponential scoring approach).  To my knowledge, the analysis of PSILCA results does not include a solution to this issue. Therefore, I would like to ask the community if there is a methodological approach to aggregate correctly at the stakeholder or impact category level. I would greatly appreciate your help or food for thought.

Best Regards

Answer 1

Hi, interesting question. Aggregation within a sector is not possible so far via the LCIA method, as you would need to distinguish by contributing process, but it should be possible via the grouping feature in openLCA, in the analysis result. You could do this for the "LCIA" result, and also for the single risk scores. You can also of course modify the exponential factors in the LCIA method, I invented them some time ago, then still for the SHDB, as the risks seem not really linear, but do not take the factor values too seriously. Let me know if these suggestions work for you, thank you.

Comments

Thank you for your quick response, Andreas. In my understanding the grouping feature in openLCA just aggregates the single indicator scores along all processes/sectors within the product system. However, you could never compare the e.g. impact category 'Corruption' with 'Contribution to Economic Development' for the sector 'Mining and Quarrying - Senegal, as the number of indicators describing the subcategory varies. I might be repeating myself. I don't necessarily need to do this in openLCA, but would calculate it manually since my product system is not that extensive. So if you are aware of a methodological approach or a reference study where such a described comparison is made, I would be glad as well.

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Small addition: I am not intending to change the valuation approach, because this exponential relationship also makes sense in my eyes. Unfortunately, it is not so simple with the aggregation or averaging.  Changing the scoring system is not the solution for me, instead I try to work with it and find a suitable way.