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Does it make any sense and is it even possible to examine the impact of a level1 independent variable (e.g. student gender) on a level2 dependent variable (e.g. mean performance), which is an aggregated variable. When I try this with Analysis: type = TWOLEVEL, the output state: THE VARIANCE OF 'mean perfomance' APPROACHES 0. FIX THIS VARIANCE AND THE CORRESPONDING COVARIANCES TO 0, DECREASE THE MINIMUM VARIANCE, OR SPECIFY THE VARIABLE AS A BETWEEN VARIABLE What should I do? 


Any variable that does not vary within clusters must be put on the BETWEEN list. These variables can be used only in the between part of the model. A variable measured on the individual level can be used in both parts of the model if it is not placed on the WITHIN list. In this way you could regress a between variable on the between part of a within variable. See Examples 9.1 and 9.2 for further information. 

Jana Nie posted on Wednesday, June 08, 2011  3:47 am



Dear Ms Muthen, is it possible to use a level 2 dependent variable if I first aggregate (mean) the data on that level two variable? 


Yes. But also try to use the latent variable (random intercept) version of this Level 2 DV. 


On the other hand, is it possible to let the amount of variance at the level1 vary as a function of a level2 variable? 


If the level 2 variable is categorical, you could use it as a grouping variable in a multiple group analysis. 


I understand that multilevel regression cannot accommodate level 2 outcomes. Without thinking, I ran the following model and am now wondering why it worked. I have not modeled any latent variables. Therefore this is multilevel regression with a level 2 outcome and not structural regression? What am I missing? BETWEEN= GCP; DEFINE: GCP = MEAN(GCP1r GCP2r GCP3 GCP4 GCP6); ECP = MEAN(ECP1r ECP2r); ANALYSIS: TYPE= TWOLEVEL; ESTIMATOR= MLR; MODEL: %WITHIN% ECP; %BETWEEN% GCP ON ECP; MC 


That limitation is true for regular multilevel software, not for multilevel modeling in Mplus. See e.g. UG ex9.4. 

Cassie Suh posted on Sunday, March 29, 2020  9:17 pm



Hello, I have multiple measurements within individuals as predictor variables but my outcome (dependent variable) was measured only at the between individual level. I think Mplus can handle this from the answer above but a) want to confirm if this is possible and b) see if my syntax is correct. Many thanks in advance. !iv1 iv2 are level 1 predictors !dv is the level 2 outcome Between = dv; Model: %within% iv1 iv2; %between% dv on iv1 iv2; 


Looks ok except you want to have iv1 WITH iv2 on Between. But you don't get much out of the twolevel model because there is nothing of interest on Within  you could just as well regress the dv on the iv cluster means in a singlelevel run with N=number of clusters. 

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