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st: rcal, measurement error model question
I'm a new user who is trying to fit a simple measurement error model to
a set of estimates from two independent surveys. The surveys are
measuring the same things. My data look like
(e1, v1) = set of 30 estimates and their variances from survey 1
(e2, v2) = set of 30 estimates and their variances from survey 2
The model I want to fit is basic:
e1 = a + b*e2 + u1
e2 = E2 + u2 (u1 and u2 are the model errors, E2 is E(e2) )
I've tried:
mkmat v2
mat D = diag(v2)
rcal (e1) (w: e2), suuinit(D)
This gives "invalid syntax". If I put some arbitrary variable x in the
model (which I don't want), this works:
rcal (e1=x) (w: e2), suuinit(D)
But rcal apparently does not allow aweights to account for v1 =
var(e1).
Is there a way to use rcal or some other procedure to fit the model
above, accounting for the fact that I have (1) estimates of variance for
both e1 and e2 and (2) no covariates measured without error to put in
the model?
Thanks in advance,
R. Valliant
U. of Maryland
[email protected]
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