Re: [Gretl-users] Sign mix-up for ordered logit
On Sat, 12 Feb 2011, Birger Baksaas wrote:
Coefficients from the Ordered Logit function are correct in gretl,
but
the signs seem to be mixed up.
According to the user guide, gretl fits an ascending cumulative odds
model. Then it predicts the odds of being at or below a particular
category. In this case the slopes for independent variables simply have
wrong signs.
I note that the gretl coefficients and cut-points (magnitude and
sign) agree with those given by Wooldridge in his Econometric
Analysis of Cross Section and Panel Data, Example 15.5 on Asset
Allocation. A script for this example is in the Gretl User's Guide
(in fact ordered probit is used, but the signs are the same for
logit). And the theoretical account of the method in the User's
Guide is, so far as I can see, fully consistent with that given by
Wooldridge. So I'm puzzled.
Allin Cottrell