Message-ID: <7E4C06F49D6FEB49BE4B60E5FC92ED7A01DA7E7A@pnlmse35.pnl.gov>
Date: 2005-05-02T21:43:02Z
From: Waichler, Scott R
Subject: Trying to understand kpss.test() in tseries package
I'm trying to understand how to use kpss.test() properly. If I have a
level stationary series like rnorm() in the help page, shouldn't I get a
small p-value with the null hypothesis set to "Trend"? The (condensed)
output from kpss.test() for the two possible null hypotheses is given
below. I don't see any significant difference between these results.
> x <- rnorm(1000) # is level stationary
> kpss.test(x, null="Level")
KPSS Test for Level Stationarity
KPSS Level = 0.0638, Truncation lag parameter = 7, p-value = 0.1
Warning: p-value greater than printed p-value
> kpss.test(x, null="Trend")
KPSS Test for Trend Stationarity
KPSS Trend = 0.0275, Truncation lag parameter = 7, p-value = 0.1
Warning: p-value greater than printed p-value
I can't get the original reference easily.
Scott Waichler
Pacific Northwest National Laboratory
scott.waichler at pnl.gov