Model with only formative LVs

Questions about the implementation and application of the PLS-SEM method, that are not related to the usage of the SmartPLS software.
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harel
PLS Junior User
Posts: 3
Joined: Mon Aug 01, 2022 4:20 pm
Real name and title: Harel Cader

Model with only formative LVs

Post by harel »

Dear SmartPLS community,

Diamantopoulos, Riefler, and Roth have shown that a PLS path model with only formative latent variables (LVs) is non-identifiable. It is also written here on the discussion forum.

I love SmartPLS, but, recently, I discovered the 'plspm' R package too. It offers two modes: A and B, which correspond to reflective and formative measurement, correspondingly. How is that possible that the 'plspm' R package estimates models with only formative LVs? How could you explain that? Are the results there correct and reliable?

For example, a model with an exogenous second-order formative LV and an endogenous formative LV can be estimated in 'plspm' R package. Then, I also added moderation there.
jmbecker
SmartPLS Developer
Posts: 1281
Joined: Tue Mar 28, 2006 11:09 am
Real name and title: Dr. Jan-Michael Becker

Re: Model with only formative LVs

Post by jmbecker »

I think that Diamantopoulos, Riefler, and Roth discuss the identification of model with formative measure in the context of CB-SEM not PLS-SEM.
In PLS-SEM you can have a model with only formative measures, because it is a composite-based estimator. Identification rules in PLS are different than in CB-SEM and you can also specify and estimate a model with only formative measures in SmartPLS.
Dr. Jan-Michael Becker, BI Norwegian Business School, SmartPLS Developer
Researchgate: https://www.researchgate.net/profile/Jan_Michael_Becker
GoogleScholar: http://scholar.google.de/citations?user ... AAAJ&hl=de
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