Different paths in social life cycle impact assessment (S-LCIA)—a classification of type II impact pathway approaches

Purpose: In social life cycle assessment (S-LCA), we can distinguish two main types of impact assessment (LCIA): type I can be seen as a reporting approach with the use of performance reference points and type II aims at including cause-effect chains or impact pathways in the analysis. Given the heterogeneity of those type II approaches, this review provides a classification of existing type II approaches. Methods: We reviewed a total of 28 articles against the background of their main purpose, the method used, the issues covered and the origin of data (observation/characterization/ measurement). We checked the articles against (i) the reflection of an impact pathway, (ii) the availability of so-called inventory and impact indicators, and (iii) the presence of characterization models or factors translating correlations or causality. Results and discussion: The analysis reveals three main paths to include impact pathways in S-LCA, which differ in authors’ intentions: (1) some studies identify and propose variables composing impact pathways, or frameworks gathering several pathways; (2) other studies investigate or test known pathways empirically, and until now seek mainly to link income data with health impacts at a macro scale, and (3) a last batch applies known and already quantified characterization models or factors from other research works in case studies. Until now, these case studies focus mainly on income-related social effects or on health impacts. Further, each path is further characterized and classified under nine approaches. Our findings highlight not only the heterogeneous nature of approaches, but also their common denominator which is to not consider phenomena or impacts in isolation but to consider them in relation to their sources or further impacts. It should be noted that type II studies are not only limited to quantitative approaches and variables, but can also use more qualitative variables and methods. Conclusions: The presented classification may be used as a guidance tool for authors to make their methodological choices. Also, our findings indicate the opportunity of extending future type II S-LCA research to variables tackled in type I studies (e.g. safe and fair employment and working conditions), beyond pathways including incomes and health impacts. This can be done by using theories from social sciences for the identification of impact pathways. Those could then further be investigated through statistical approaches or in the framework of S-LCA case studies, with specific data and potentially more qualitative methods to analyze causality or social mechanisms.