Dear Gretl users, I have a question about system estimation and a (possible) bug report. The question is: is it possible to include weights for observations when estimating a system of equations in gretl (with sur method for example)? I've read in the command reference that the supported estimators are ols, tsls, sur, 3sls, fiml and liml. However, if I estimate the system using the "simultaneous equations" dialog box, there is also wls as one of the proposed estimators (but it's not possible to specify a weight variable, so maybe it does not perform a weighted regression after all).

The possible bug occurs after the estimation of a system using method SUR. In the results window, the command "Tests -> Normality of residuals" is active, but nothing happens when I click on it (gretl does not crash either).

On Wed, 29 Apr 2015, Simona De Lauretis wrote: Dear Gretl users, > > I have a question about system estimation and a (possible) bug report. > > The question is: is it possible to include weights for observations when > estimating a system of equations in gretl (with sur method for example)? > > I've read in the command reference that the supported estimators > are ols, tsls, sur, 3sls, fiml and liml. However, if I estimate the > system using the > "simultaneous equations" dialog box, there is also wls as one of the > proposed estimators > > (but it's not possible to specify a weight variable, so maybe it does > not perform a > weighted regression after all). > Thanks for the report. The "wls" option has somehow slipped through undocumented, we need to fix that. But it's not intended that the user can supply weights, rather the idea is that weights are derived from the relative variances of the error terms in the equations of the system. It's the same use of "wls" as in the systemfit package for R, in case you've come across that. See http://cran.r-project.org/web/packages/systemfit/systemfit.pdf for brief documentation. The possible bug occurs after the estimation of a system using method > SUR. In the results window, the command "Tests -> Normality of residuals" > is active, but nothing happens when I click on it (gretl does not crash > either). > I see what you mean. For some reason the normality test via the GUI was not hooked up to its "callback" to actually do the job (or actually, was hooked up only for models estimated on time-series data). That's now fixed in CVS and gretl snapshots. Allin Cottrell _______________________________________________ Gretl-users mailing list Gretl-users(a)lists.wfu.edu http://lists.wfu.edu/mailman/listinfo/gretl-users

On Thu, 30 Apr 2015, Ignacio Diaz-Emparanza wrote: > [...] > Thank you, Allin. > > When you have time and if it is not excesively time-consuming, it > would be good to add an option for importing the "Linear series" from > TRAMO/SEATS results. This is the series with outlier and missing > values corrected. (We could then consider 'Tramolin' package > deprecated). OK, that's now in CVS, along with a linearize() function which takes a series as input and returns the TRAMO linearization (not yet documented). These things may need some tweaking, but I've checked against Tramolin and they seem to produce the same output -- except when the sample range is restricted before calling the functions, but I think there's a bug in Tramolin for that case. Try comparing: <hansl> include tramolin.gfn open data9-3.gdt smpl 1979:3 ; series price_l1 = tramolin(price) series price_l2 = linearize(price) print price price_l1 price_l2 --byobs </hansl> Allin