[Rsiena-help] SIENA: rate function with large s.e.

[Christian Steglich]

Hi Philippe,

your result suggests that behaviour change is very quick compared to 
network change, i.e., that according to the given model specification (a 
very sparse one), the first behaviour measure is actually 
non-informative for explaining the evolution to the second behaviour 
measure.

This could be due to several things: actor heterogeneity when the model 
assumes homogeneity, some other type of model misspecification, use of 
an inflated behaviour scale (your parameters are very small, suggesting 
as much), or true independence in your behaviour responses. I'd suggest 
you check the micro step distribution first (who makes how many steps in 
which direction) for any anomalies.

Best,
Ch



Am 14/07/2012 18:06, schrieb Philippe Sulger:
> Dear RSiena-Users
>
> I jointly analyze network dynamics and behavioral dynamics. Something 
> that I am concerned about are the large standard errors on the 
> estimate of the behavioral rate parameter. Here an example:
>
>                                                   Estimate Standard   
> Convergence
> Error      t-ratio
> Network Dynamics
>    1. rate  basic rate parameter friends           7.8441  ( 1.3870  
> )    0.0131
>    2. eval  outdegree (density)                   -1.1287  ( 0.1991  
> )   -0.0392
>    3. eval  reciprocity                            1.8075  ( 1.1237  
> )    0.0220
>    4. endow reciprocity                           -1.7207  ( 1.9371  
> )   -0.0050
>    5. eval  balance                                0.2603  ( 0.0565  
> )    0.0264
>    6. eval  same covariate                         0.2877  ( 0.2220  
> )    0.0135
>
> Behavior Dynamics
>    7. rate  rate behav period 1                   34.9277  ( 36.6589  
> )   -0.0177
>    8. eval  behavior behav linear shape           -0.0327  ( 0.0592  
> )   -0.0194
>    9. eval  behavior behav quadratic shape         0.0003  ( 0.0048  
> )   -0.0220
>   10. eval  behavior behav: effect from covariate -0.0096  ( 0.1383  
> )   -0.0588
>
> As you see, convergence is good. Even if I exclude the 10th effect 
> (effect from gender, in many networks I get large s.e. for the rate on 
> aggressive behavior). I also made the rate of behav dependent on 
> covariates with no essential effect.
>
> Are these large s.e.'s of concern?
>
> Thanks for your help.
>
> Best,
> Philippe
>
>
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-- 
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Christian Steglich, researcher
Faculty of Behavioural and Social Sciences
University of Groningen
Grote Rozenstraat 31
9712 TG Groningen
The Netherlands

fon +31-(0)50-363 6189
fax +31-(0)50-363 6304

http://www.gmw.rug.nl/~steglich/
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