Multi-path General-to-Specific (GETS) modelling of the mean and/or variance of a regression, and Indicator Saturation (ISAT) methods for detecting structural breaks in the mean. The mean can be specified as an autoregressive model with covariates (an 'AR-X' model), and the variance can be specified as a dynamic log-variance model with covariates (a 'log-ARCH-X' model). For the statistical details of the model, see Section 4 in Pretis, Reade and Sucarrat (2018).
The main functions of the package are arx
, getsm
, getsv
and isat
. The first function, arx
, estimates an AR-X model with (optionally) a log-ARCH-X specification on the log-variance. The second function, getsm
, undertakes GETS model selection of the mean specification of an arx
object. The third function, getsv
, undertakes GETS model selection of the log-variance specification of an arx
object. The fourth function, isat
, undertakes GETS model selection of an indicator saturated mean specification. Extraction functions (mainly S3 methods) are also available, together with additional auxiliary functions used by the main functions.
For an introduction to the package, see Pretis, Reade and Sucarrat (2018): https://www.jstatsoft.org/article/view/v086i03. The package also provides facilities for user-defined GETS and ISAT methods. While this is to some extent available via the main functions, full flexibility is provided by getsFun
and blocksFun
, see Sucarrat (2019): https://mpra.ub.uni-muenchen.de/96653/.