st: event history analysis with years clustered in individuals

[Hilde Karlsen <Hilde.Karlsen@hio.no>]

Dear statalisters,

This is probably a stupid question, but I've been searching around the 
nets and in books and articles, and I've still not grasped the concept: 
When I'm performing a multilevel analysis of attrition from nursing 
using xtmelogit, and time (year) is the level 1 variable and individuals 
(id) is the level 2 variable (i.e. years are clustered within 
individuals; I have a person-year file), how do I formulate the 
expectation related to this model? Why is it important to separate 
between these two levels?

I find it more intuitive to grasp the fact that individuals are 
clustered within schools, and that variables on the school level - as 
well as variables on the individual level - may influence e.g. which 
grades a student gets.

I understand (at least I hope I understand) the point that when the same 
individuals are followed over a period of time,  the individual's 
responses are probably highly correlated, and that this  implies a 
violation to the assumption about the heteroskedastic error-terms. As I 
see it, I could have used the cluster() - command (cluster(id))to 
'avoid' this violation; however, I have to write an essay using 
multilevel analysis, so this is not an option.

I don't know if I'm being clear enough about what my problem is, but any 
information regarding this topic (how to grasp the concept of years 
clustered in individuals) will be greatly appreciated.
I'm really sorry for having to ask you such an infantile question.. My 
colleagues and friends are not familiar with multilevel analyses, so I 
don't know who to turn to.

Best regards,
Hilde
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