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This class contains the relevant information by applying the Kwiatkowski, Phillips, Schmidt and Shin unit root test to a time series.

Slots

y:

Object of class "vector": The time series to be tested.

type:

Object of class "character": Test type, "mu" or "tau" depending on the deterministic part.

lag:

Object of class "integer": Number of lags for error term correction.

cval:

Object of class "matrix": Critical value of test.

teststat:

Object of class "numeric": Value of test statistic.

res:

Object of class "vector": Residuals of test regression.

test.name:

Object of class "character": The name of the test, i.e. `KPSS'.

Extends

Class urca, directly.

Methods

Type showMethods(classes="ur.kpss") at the R prompt for a complete list of methods which are available for this class.

Useful methods include

show:

test statistic.

summary:

like show, but critical values, lags and test type added.

plot:

Residual plot and their acfs' and pacfs'.

References

Kwiatkowski, D., Phillips, P.C.B., Schmidt, P. and Shin, Y., (1992), Testing the Null Hypothesis of Stationarity Against the Alternative of a Unit Root: How Sure Are We That Economic Time Series Have a Unit Root?, Journal of Econometrics, 54, 159–178.

Download possible at: https://cowles.yale.edu/, see rubric 'Discussion Papers (CFDPs)'.

See also

Author

Bernhard Pfaff