st: Murphy Topel for OLS in first stage and in second stage

["Andreas Tiltag" <tiltag@iaaeg.de>]

Dear Statalist,

can anybody give me a reference / a formula / Stata code for the standard 
error correction in two-step estimations according to Murphy and Topel 
(1985) when the first and the second stage are estimated by OLS?

In Murphy and Topel and other Papers, I only find formulas for the first 
step estimated by maximum likelihood.

Thanks a lot,

Andi 
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