Hi Max,
I read that paper (and now even more closely) and confess to still not fully understand what it refers to. Perhaps it escapes me, but let us take the example of European democracies.
First of all, I simply do not believe there is any scale of democracy whatsoever that would ever include an item regarding the geographical location. An operational model of democracy includes potenatially multiple items, but none of those is location. I am not an expert and would be delighted to stand corrected, but as far as I am aware such a thing simply does not exist.
Hence their statement that "Canada’s set membership is zero and not 0.5 as the average" strike as odd, as it would never cross my mind to attempt such a location based aggregation.
Instead:
- I would first compute a (raw) score of democracy on Canada, using sumation, mean or whatever other aggregation method seems theoretically justified (thus obtaining an interval level, numeric score), then
- compute the set membership score for Canada (in the set of democratic countries) using the direct or indirect method, provided the raw score is interval numeric, and only then
- compute the set intersection between: the membership in the set of European countries and the membership in the set of democratic countries, correctly resulting zero (and not 0.5 as they seem to suggest).
Their second point that "...averaging different variables to capture a concept is based on the assumption that all indicators are equally important for a concept" is absolutely valid.
But yet again, as far as I am aware there is no methodological indication that average is the best aggregation method. Quite the contrary, there are numerous examples (for instance the Human Development Index) where different dimensions of the concept have different weights in the final aggregated score.
Whatever the aggregation, linear or weighted, the method would always produce an interval level raw score. And it is perfectly possible to compute a set membership based on that score, using Ragin's methods.
I really, really see no problem at all using this approach, but I might as well completely misunderstood Emmeneger, Schraf and Walter (2014) and apologize in advance if doing so.
But if I am right, then everything I mentioned in the previous messages should still be valid. I don't think there are different schools of set theoretical thinkers, just those following (proper?) methodology... or something else. Using established scales does not make some more "quantitative" than others, for set-theoretical thinking makes as all comparativists.
Best,
Adrian
> On 2 Apr 2020, at 13:47, Max Netherworlds <
max.neth...@gmail.com> wrote:
>
> Hey Adrian,
>
> I aggree with you that averaging/summing up of scales is established and works for a lot of set-theoretic questions. My concerns base on a working paper by Emmenegger et al. 2014 (Emmenegger, Patrick; Schraff, Dominik; Walter, André (2014): QCA, the Truth Table Analysis and Large-N Survey Data: The Benefits of Calibration and the Importance of Robustness Tests. In: Compasss Working Paper (2014-79)., which I want to quote here:
>
> "Set-theoretic approaches also have an untapped potential with regard to the combination of multiple survey items. When a concept cannot be measured by a single indicator, it is common procedure in studies using regression-based approaches (but oddly enough also in studies using set-theoretical methods) to simply use the average of different variables or to conduct a factor analysis of variables that are expected to be in a causal relationship with the latent concept (for QCA studies using such inductive procedures see Berg-Schlosser 2008; Cárdenas 2012; Cheng et al. 2013; Crowley 2013; Engeli 2012; Grendstad 2007; Vaisey 2007). However, using such an inductive approach to capture sets is problematic for at least two reasons.
> First, while indicators are typically numeric, concepts are constructed in terms of necessary and sufficient conditions (Goertz 2006). For instance, Canada is not a member of the category European democracies because Canada, although democratic, is not a European country. Hence, Canada’s set membership is zero and not 0.5 as the average of the variables ‘democratic’ and ‘European’ might imply. Hence, the calibration of sets by means of linear algebra is highly susceptible to misclassification, while conceptual thinking implies that variables are combined in a logical fashion using AND/OR operations. If the conceptual structure of necessary and sufficient conditions is not reflected in the measurement process, the result is concept-measure inconsistency. In our empirical example, scholars typically relied on inductive approaches, thus leaving conceptualization underdeveloped and resulting in large number of empirical work which is conceptually only loosely connected.
> Second, averaging different variables to capture a concept is based on the assumption that all indicators are equally important for a concept. For instance, opposing immigration from poor Asian or African countries has the same weight as the opposition towards immigration from rich, neighbouring European countries. However, this line of argumentation is hardly justifiable for a number of reasons, which we discuss below." (pp. 9–10)
>
> According to this, there seem to be different "schools" of set-theoretic thinkers, when it comes to the collection of data and subsequent calibration: Some rely on established scales, proofed as reliable with correlation-based parameters of fit such as Cronbach's alpha, and their linear combination. Others (such as Emmenegger et al.) seem to challenge this by stating that it comes from a correlation-based thinking that contrasts set-theoretic thinking. They rely on a conceptual informed calibration and aggregation. Perhaps you could call the former "quantitative", that latter "qualitative".
>
> What is your opinion to this debate? Do you think both approaches have their legitimation?
>
> Best,
> Max