does Rats have quasi-MLE function?

Econometrics questions and discussions

does Rats have quasi-MLE function?

Postby Frank » Thu Jun 17, 2010 10:34 am

as the title,
parameters estimated by MLE is assumed the distribution follows normal distribution.
however, if we set the distribution follow non-normal one, then, we have to apply quasi-MLE.
But, I couldn't find the function of QMLE in WinRats. does it have this function?
or we don't have to account this issue?

Can someone answer me this ? thanks a lot.

Frank
Frank
 
Posts: 4
Joined: Fri Jun 11, 2010 7:18 am

Re: does Rats have quasi-MLE function?

Postby TomDoan » Thu Jun 17, 2010 2:47 pm

With QMLE, you maximize a likelihood that you either know or suspect is misspecified using standard methods. However, there are quite a few situations where the misspecified likelihood is adequate for obtaining consistent estimates of the parameters - an obvious example would be least squares, which is the MLE for i.i.d. Gaussian disturbances, but consistent under much broader circumstances.

While the parameter estimates might be consistent, a covariance matrix that comes from the inverse of the information matrix won't be correct. In general, the ROBUSTERRORS option corrects for the failure of the information equality when you're not using the correct likelihood. That's available on DDV, GARCH, LDV, MAXIMIZE, NLLS, NLSYSTEM and SUR, as well as LINREG.

I've attached some fairly generic lecture notes on QMLE. (These are from the State Space/DSGE course materials). As described above, the general treatment with RATS is to use your standard instruction for estimation, but include the ROBUSTERRORS option.

QMLE Notes.pdf
(245.5 KiB) Downloaded 190 times
TomDoan
 
Posts: 2720
Joined: Wed Nov 01, 2006 5:36 pm


Return to General Econometrics

Who is online

Users browsing this forum: No registered users and 1 guest