Can we do something about the confusing/ambiguous [random-effects-model] and [fixed-effects-model] tags?

Question

I want to discuss the following three tags: mixed-model (2000+), random-effects-model (580) and fixed-effects-model (400).

There is a well-known terminological ambiguity between econometrics and other statistics with regards to the "random effects" and "fixed effects". I feel that our tags add to this ambiguity, instead of clearing it up.

• Mixed models are linear models that include random effects and fixed effects, i.e. random factors and fixed factors (or, rarely, only random factors). The terms "random/fixed effects model" are never (?) used to refer to mixed models. Update: Mixed models are also sometimes called "random effects models".

• In econometrics, a "fixed effects model" is a way to treat panel data which is equivalent to a standard linear model with only fixed effects. In contrast, a "random effects model" is a way to treat panel data which is formally equivalent to a mixed model with a random intercept but which is estimated via FGLS and not via MLE (as mixed models are). (Evidence: @StasK's 2012 Meta answer and my recent question on the main site.)

So conceptually [fixed-effects-model] tag should only be applied to questions about econometrics; in practice people often use it on questions about mixed models to refer to fixed effects. This is confusing. And [random-effects-model] tag can be, and is being used to refer to both, mixed models and random effects models in the econometrics sense. So the mixed models questions get split between these two tags, which is very unfortunate.

What could be the ideal arrangement?

I'd say: rename these two tags such that they unambiguously refer to econometrics. For example: [panel-random-effects] and [panel-fixed-effects] (the word "econometrics" is too long to include in a tag name). And sort out the mixed models questions into [mixed-model].

Answer 1

My question did not provoke much interest but I am still deeply annoyed by the current situation.

Here is what seems to me would be a better arrangement:

1. random-eff-econometrics
   For questions about "random effects model" in econometrics. This means a model with random intercepts which is estimated with FGLS.

2. fixed-eff-econometrics
   For questions about "fixed effects model" in econometrics. This actually means a simple linear model, but usually it is of a particular form and is estimated in a particular way.

3. random-eff-in-mixed-model$\to$mixed-model
   fixed-eff-in-mixed-model$\to$mixed-model
   For questions about random effects and fixed effects in mixed models. We don't need separate tags for that, so these should be synonyms of the existing [mixed-model] tag.

With this arrangement, anybody typing "random-e..." in the tag field will get two suggestions and will be able to choose an appropriate one. The current tags random-effects-model and fixed-effects-model should be sorted out and eliminated. I don't see any disadvantage of my suggested arrangement, but I see multiple advantages (e.g. all questions about mixed models will be under [mixed-model] instead of being divided between [mixed-model] and [random-effects-model]).

@StasK wrote back in 2012 that

May be there should be random-effects-model-econometrics and fixed-effects-model-econometrics subtags

which is in line with what what I am suggesting here. The tag names have to be shorter though, due to the 25 chars limit.

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This would require a substantial retagging effort but I would volunteer to do it. I looked the last 50 questions in both tags, and here is how they are split between topics:

                             econ      MM      both     neither      sum
 fixed-effects-model:         37       8       -        5            50
 random-effects-model:        15       35      -        -            50

Based on that, I would take the mixed-model Qs out of fixed-effects-model, and the econometrics Qs out of random-effects model, and then we could do tag renames for the rest.

There are 1001 threads tagged with either of these tags. The fraction to be manually retagged is ~15/50. So it's 1000*15/50 = 300 threads. With 10/day it will take 1 month.