Search found 427 matches

by GeorgeLeckie
Thu Jan 11, 2018 9:40 am
Forum: runmlwin user forum
Topic: Stata 15 runmlwin problem
Replies: 3
Views: 1590

Re: Stata 15 runmlwin problem

As a follow on from our previous post, we note that an additional error arises when one specifies the correlations option. The correlations option requests the estimated school-level covariance between the random intercepts and slopes to be reexpressed as a correlation. In Stata 15 this option no lo...
by GeorgeLeckie
Wed Dec 13, 2017 2:00 pm
Forum: runmlwin user forum
Topic: Stata 15 runmlwin problem
Replies: 3
Views: 1590

Re: Stata 15 runmlwin problem

Dear Kate, You are correct. The phenomenon that you refer to relates to using runmlwin in Stata 15. Essentially random effects covariance parameters are incorrectly presented as variance parameters in the model output. The problem is brought about by a bug introduced by Stata in version 15. They are...
by GeorgeLeckie
Thu Aug 31, 2017 12:18 pm
Forum: runmlwin user forum
Topic: Error message: too many macros
Replies: 10
Views: 5430

Re: Error message: too many macros

Dear rdmcdowell, The way you describe is the correct way. This allows full flexibility. You can switch whichever elements you like on and off via this approach and you can specify whatever linear constraints you like. The downside is that this entails quite a lot of syntax and appreciate this is fru...
by GeorgeLeckie
Fri May 12, 2017 4:18 pm
Forum: MLwiN user forum
Topic: Question about ICC
Replies: 1
Views: 716

Re: Question about ICC

Dear Sherry08, If you have found a neighbouhood level ICC of 0.96 for BMI, then I suggest something has gone wrong in your calculation. I would expect something more like 0.05! The ICC is the correlation between two randomly selected individuals' BMI from the same neighbourhood and so we would never...
by GeorgeLeckie
Thu Mar 23, 2017 2:27 pm
Forum: runmlwin user forum
Topic: stata imputed data in mlwin
Replies: 4
Views: 2607

Re: stata imputed data in mlwin

Dear Rodrigo, Suggest you run the mo estimate command with the noisily option and inspect each set of model results. It may well be the case that one of your variance components gets stuck on zero on one or more iterations. mi estimate then complains as it assumes that the parameter stuck on zero ha...
by GeorgeLeckie
Tue Mar 07, 2017 6:33 pm
Forum: MLwiN user forum
Topic: homoscedasticity assumption in logistic models?
Replies: 2
Views: 1536

Re: homoscedasticity assumption in logistic models?

Dear adeldaoud, Yes there is no level-1 residual in the linear predictor of a two-level random-intercept logistic regression and so we only assess the distributional assumption of the level-2 random effect, namely that it is normally distributed and homoskedastic. You can assess the plausibility of ...
by GeorgeLeckie
Thu Feb 23, 2017 5:08 pm
Forum: MLwiN user forum
Topic: Problem with correlation between intercept and slope
Replies: 1
Views: 993

Re: Problem with correlation between intercept and slope

Hi Max, The correct correlation to report is the one based on the estimated variances and co-variances. The correlation based on the predicted random effects differs in part due to the fact these are shrinkage estimates. You should find some coverage of this in various multilevel text books. As an a...
by GeorgeLeckie
Sun Feb 19, 2017 1:31 pm
Forum: runmlwin user forum
Topic: coefficients and variance partition differs considerably between runmlwin and melogit
Replies: 2
Views: 1517

Re: coefficients and variance partition differs considerably between runmlwin and melogit

Dear Lisa, The differences you see relate to the severe clustering exhibited in your data. MLwiN's default estimation method for binary and other categorical and count response models is quasilikelihood estimation and comes in four flavours of increasing accuracy, MQL1 (default), MQL2, PQL1 and PQL2...
by GeorgeLeckie
Tue Jan 24, 2017 10:07 am
Forum: runmlwin user forum
Topic: Use of predict and margins post-estimation
Replies: 1
Views: 1651

Re: Use of predict and margins post-estimation

Hi Marie,

I'm afraid you will have to make your graphs from first principles. We have not done anything in runmlwin to allow margins to work with it; it is a non-trivial task.

Best wishes

George
by GeorgeLeckie
Fri Jan 06, 2017 4:36 pm
Forum: MLwiN user forum
Topic: interpreting main effect in random slopes model
Replies: 1
Views: 1096

Re: interpreting main effect in random slopes model

Dear emazel90, I would keep the time trend in the fixed-part of the model even if the slope is not significant. The fixed-part time trend is such a fundamental part of the model, it would look odd to remove it, even though it is not significant. Essentially the population mean does not change over t...