On Tue, 26 Oct 2004, Blaise Roncagli wrote:

> Thanks for the quick response.  I have attached a dataset called 
> "sampledata.xls"...

I'm currently trying to do a comparison of GARCH results from gretl 
and R (the ARMA results seem pretty much the same).

My problem at present is that I can't get R to produce any sensible 
GARCH estimates.  I'm using R 2.0.0 on Linux, with the "tseries" 
library version 0.9-23.  With Blaise's two series, and also with the 
benchmark Bollerslev-Ghysels dataset, the GARCH "a1" and "b1" 
estimates are printed as "0.050000", regardless of the particular 
series used.  (I have printed the series out from R to check that 
the data are right.)  The B-G results do not remotely resemble the 
benchmark results.

I'm using the defaults (1,1), as in:

y.garch <- garch(y)
summary(y.garch)

Any ideas on what I might be doing wrong?

Allin Cottrell

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