Date:         Sun, 17 Jun 2007 23:01:33 -0700
Reply-To:     David L Cassell <davidlcassell@MSN.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         David L Cassell <davidlcassell@MSN.COM>
Subject:      Re: proc qlim
In-Reply-To:  <1182027223.815500.166280@n60g2000hse.googlegroups.com>
Content-Type: text/plain; format=flowed

apan14@GMAIL.COM wrote:
>
>Hello,
>
>Can anyone let me know what the SIGMA signifies in the OUTPUT Results
>after running a PROC QLIM in order to estimate a tobit model ???
>
>Thank you in advance
>
>Anurag

In a typical tobit model in PROC QLIM, you have a censored regression
model.  You have

z = b0 + b1*X1 + ... + bn*Xn + e
and
y = z if z>0  (y=0 otherwise).

So the parameter _SIGMA is the standard deviation of that normal error
e from your theoretical model.

HTH,
David
--
David L. Cassell
mathematical statistician
Design Pathways
3115 NW Norwood Pl.
Corvallis OR 97330

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