when I try to estimate a PARCH model (GARCH model with option PARCH), I get the following error message: "Attempt to raise a negative number to a non integer power in "EQUATION PERCEQ.ARCH(1,1,PARCH) PERCR. The data file is addtached, the code itself is very simple:
Code: Select all
wfopen 6.csv
genr logr = dlog(abs(prc)/cfacpr)
genr percr = @pch(abs(prc)/cfacpr)
equation logeq.ARCH(1,1,parch) logr
equation perceq.ARCH(1,1,parch) percr
Surprisingly, I have this problem only with percentage returns, parch model with logaritmic returns works fine. This seems to be really strange, since percentage and relative returns are very similar.
Is there bug in estimation of PARCH model, or am I just misunderstanding something?