Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: RE: selection correction factors after heckprob


From   "Ypma, Jelmer Yeb" <[email protected]>
To   <[email protected]>
Subject   st: RE: selection correction factors after heckprob
Date   Wed, 15 Dec 2004 12:04:42 -0800

Hi,

I don't know the answers to all of your questions, but I'll give a shot at two of them

> What is the athrho for? 

As far as I know the athrho is used in the maximization process. rho is usually calculated as follows
rho = [exp(2*athrho)-1]/[exp(2*atrho)+1] 
This means that athrho can take on any value from minus infinity to infinity and rho will still have a value between -1 and 1.

> Particularly, I am concerned whether "binorm" command is appropriate in calculating the bivariate normal distribution with the correlation term rho.

-binorm- (according to the reference guide, see functions -> probability distributions and densitiy functions)
description: returns the joint cumulative distribution \Phi(h, k, rho) of bivariate normal, with correlation rho; cumulative over (-infty, h]x(-infty,k];

Good luck!

Jelmer

--------------------

This email message is for the sole use of the intended recipient(s) and
may contain privileged information. Any unauthorized review, use,
disclosure or distribution is prohibited. If you are not the intended
recipient, please contact the sender by reply email and destroy all copies
of the original message.



*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2024 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index