Search found 156 matches

by billb
Wed Mar 17, 2021 6:53 pm
Forum: MLwiN user forum
Topic: Nested models with fixed - sort of - categories
Replies: 2
Views: 8251

Re: Nested models with fixed - sort of - categories

Hi John, It is quite common for people to fit random effects to a set of units even if the sampled units are in fact the population. Arguments are made that for example the data is a snapshot in time and thus there would be random uncertainty. A good example is voting data where the dataset is often...
by billb
Sun Jan 24, 2021 11:32 am
Forum: MLwiN user forum
Topic: Error when fitting a multinomial logit regression with panel data
Replies: 17
Views: 27834

Re: Error when fitting a multinomial logit regression with panel data

Hi Ferhat,
Happy to take a quick look if you send me the worksheet (william.browne@bristol.ac.uk). We are running a workshop this week so may not be able to get back immediately.
Bill.
by billb
Fri Jan 22, 2021 6:06 pm
Forum: MLwiN user forum
Topic: Error when fitting a multinomial logit regression with panel data
Replies: 17
Views: 27834

Re: Error when fitting a multinomial logit regression with panel data

Hi Ferhat, Looking at your variance matrix ALL elements were 0 this means you need to make the matrix positive definite. I think in other places I have suggested making sure the off-diagonal values are 0 which will ensure all correlations are 0 HOWEVER you do need to have all the elements on the dia...
by billb
Fri Jan 22, 2021 2:26 pm
Forum: MLwiN user forum
Topic: Error when fitting a multinomial logit regression with panel data
Replies: 17
Views: 27834

Re: Error when fitting a multinomial logit regression with panel data

Hi FerhatTura, Chris passed on your query to me but I am not sure how much extra help I can be. Essentially to run the model in MCMC you first need to ensure that the starting values are plausible i.e. that variances are positive and that any covariance matrix is positive definite (essentially that ...
by billb
Tue Jan 12, 2021 2:40 pm
Forum: MLwiN user forum
Topic: Error when fitting a multinomial logit regression with panel data
Replies: 17
Views: 27834

Re: Error when fitting a multinomial logit regression with panel data

Hi, So no the data is 2-levels it is just that for fitting both multivariate response models and multinomial models MLwiN expands out the data to create a dummy level of categories/responses below level 1. The reason you are getting an error message is that when you use year within individual MLwiN ...
by billb
Fri Dec 04, 2020 9:49 am
Forum: runmlwin user forum
Topic: Variance Decomposition
Replies: 3
Views: 9907

Re: Variance Decomposition

Sounds good and great that you get similar results to lme4. I think as long as you ensure you have unique ids everything will be fine i.e. not using the Execid number for different indiviudals in different Industries. I would then take a look at how multiple-membership works in MLwiN as you will req...
by billb
Thu Dec 03, 2020 1:46 pm
Forum: runmlwin user forum
Topic: Variance Decomposition
Replies: 3
Views: 9907

Re: Variance Decomposition

Hi Lmcrace, Yes it sounds like you may have cross classifications and multiple memberships. My only question would be whether these different 'effects' are all identifiable and how big your data is. For example I can think in education of a dataset with kids nested within classes and teachers but if...
by billb
Mon Nov 23, 2020 5:21 pm
Forum: MLwiN user forum
Topic: About multivariate response model
Replies: 1
Views: 7699

Re: About multivariate response model

Dear Tomay, I would suggest that you take a look through the manual about multilevel multivariate responses. 1. When you add predictor variables you can as you correctly point out add them as common coefficient which (at least for IGLS) will give you the same effect for A and B. 2. Yes just make sur...
by billb
Thu Oct 08, 2020 7:30 pm
Forum: MLwiN user forum
Topic: Detecting significant results
Replies: 6
Views: 11120

Re: Detecting significant results

Hi Sabine,
I am afraid outside of MCMC you are stuck with the approximate Wald test (which essentially assumes normality) of equivalently the P values spat out by the Store model window which does likewise.
Best wishes,
Bill.
by billb
Thu Oct 08, 2020 1:36 pm
Forum: MLwiN user forum
Topic: Detecting significant results
Replies: 6
Views: 11120

Re: Detecting significant results

Hi Sabine, Not sure I follow your question - the interval and tests window will give you a P value if we are still talking about the same model but you need to tell it what Wald test to perform (there is something about this window in the help system and an example in the binary response chapter of ...