HET

The HET command implements the estimation of models which require correction for heteroskedastic errors.

In general, the format is:

  HET depvar indeps (exogs) / options


The available options are:

Option Description
PRESAMP Sets the initial value for the presample data in all iterations.
ARCH= Specifies the order q of the ARCH process.
ARCHM= Specifies the functional form for the ARCH-in-Mean term. Set ARCHM=0 for the log of the variance function and set ARCHM=0.5 for the square root of the variance function.
GARCH= Specifies the order p of the lagged conditional variances in the GARCH process.
GMATRIX= Specifies an NxK matrix to use to store the derivatives of the log-likelihood function at each observation. This option is not available with the NUMERIC option.
MACH= Specifies the order of the moving average process in models with ARCH errors.
MODEL= Specifies the form of heteroskedasticity.
Available options are:
ARCH - for ARCH models
DEPVAR - Dependent Variable Heteroskedasticity
MULT - Multiplicative Heteroskedasticity
STDLIN - Standard Deviation is a linear function of exogenous variables
VARLIN - Variance is a linear function of exogenous variables
START= Specifies a vector of starting values for the estimation.
STDRESID= Saves the standardized residuals in the variable specified.

Other available options are:
DUMP, LININV, LINLOG, LIST, LOGINV, LOGLIN, LOGLOG, MAX, NOCONSTANT, PCOR, PCOV, RSTAT, BEG=/END=, COEF=, COV=, PREDICT=, RESID=, STDERR= and TRATIO= as defined for the OLS command.  NUMCOV, NUMERIC, OPGCOV, CONV=, ITER=, METHOD=, PITER= and STEPSIZE= as defined for the NL command.

Temporary variables that are available are:
$ERR, $K, $LLF, $N and $R2OP