sbur_gls

Purpose

Computes the unit root stratistics with structural breaks in a GLS-detrended framework.

Format

sbOut = sbur_gls(y, model[, sburCtl])
Parameters:
  • y (Tx1 vector) – Time series with the variable to be analysed.
  • model (Scalar) – Model to be implemented.
  • nbreak (Scalar) – Optional, number of breaks to consider (up to 5). Default = 5.
  • sburCtl –

    Optional, an instance of the sburControl structure, containing the following members:

    sburCtl.knownBreaks scalar, specifies if breaks are known or unknown. 0 for known breaks, 1 for unknown breaks. Default = 1.
    sburCtl.breakDate vector, holds an known breaks dates. Default = none specified.
    sburCtl.numberBreaks scalar, when the structural breaks are unknown, this scalar indicates the number of structural breaks that is assumed. Note that, at the moment, the procedure is designed for up to m <= 5 structural breaks.
    sburCtl.penalty scalar, indicates the penalty function that defines the information criteria that is used to determine the number of lags used to estimate the long-run variance. penalty = 0 for maic, and penalty = 1 for bic. Default = 0.
    sburCtl.kmax scalar, denotes the maximum number of lags that is used to estimate the long-run variance. Default = 4.
    sburCtl.kmin scalar, denotes the minimum number of lags that is used to estimate the long-run variance. Default = 0.
    sburCtl.estimation scalar, specifying the estimation method. 0 indicates brute force estimation, 1, uses the dynamic algorithm. Default = 0;
    sburCtl.prewhit scalar, Set to 1 if want to apply AR(1) prewhitening prior to estimating the long run covariance matrix. Default = 0.
    sburCtl.maxIters scalar, if dynamic algorithm is used, this indicates the maximum number of iterations. Default = 100;
Returns:

sbOut –

An instance of the sburOut structure, containing the following members:

sbOut.pt scalar, the value for the Pt unit root test.
sbOut.mpt scalar, the value for the MPT unit root test.
sbOut.adf scalar, the value for the ADF unit root test.
sbOut.za scalar, the value for the ZA unit root test.
sbOut.mza scalar, the value for the MZA unit root test.
sbOut.msb scalar, the value for the MSB unit root test.
sbOut.mzt scalar, the value for the MZT unit root test.
sbOut.min_tb Vector, the estimated break points.
sbOut.cbar scalar, the value of the c_bar parameter that is used in the quasi GLS-detrending.
rtype sbOut:struct

Examples

library tspdlib;

// Load data
data = loadd(getGAUSSHome() $+ "pkgs/tspdlib/examples/ts_examples.csv", "Y + date($Date, '%b-%y')");

/*
** This section sets parameters
** for testing.
*/
// Set up control structure
struct sburControl sburCtl;
sburCtl = sburControlCreate();

// Number of breaks
sburCtl.numberBreaks = 2;

// Model to use
model = 3;

/*
** Estimation method
** when = 1 we use the algorithm,
** and = 0 brut force
*/
sburCtl.estimation = 1;
sburCtl.maxIters = 20;

// Output structure
struct sburOut sbOut;
sbOut = sbur_gls(data[., "Y"], model, sburCtl);