COINT

The COINT command implements tests for unit roots and cointegration

In general, the format is:

  COINT vars / options

where vars is a list of variable names.


The available options are: 

Option Description
DN Use a divisor of N (rather than N-K) when estimating the variance used in calculating the t-statistics.
DUMP Gives output of interest to SHAZAM consultants.
LOG Takes logs of the data.
MAX Gives more detailed ouptut.
BEG= Specifies the BEGinning and ENDing observations to be
END= used in the calculations. This option overrides the SAMPLE command and defaults to the sample range in effect.
NDIFF= Specifies the order of differencing to transform the the data for unit root tests.
NLAG= Specifies the number of lag terms in the Dickey-Fuller regressions or the truncation lag parameter for the Phillips tests. If this is not specified then the order is set as the highest significant lag order from either the ACF or PACF of the first differenced series.
RESID= Specifies a matrix to save the residuals from the regression equations used for the unit root tests. The first column is the residuals from the constant, no trend regression and the second column is the residuals from the constant, trend regression for the first series. The third and fourth column are the residuals for the second series (if requested). For example, to inspect the ACF of the residuals the following SHAZAM commands could be used. 

DEMO
SAMPLE
1 17 
COINT
CONSUME PRICE / NLAG=2 RESID=EMAT SIGLEVEL=5 
* Adjust the sample period for the observations lost due to lags
 
GEN1
BEG=4 
GEN1
END=17 
GEN1
NOBS=END-BEG+1 
SAMPLE
1 NOBS 
DO
#=1,4 
    COPY
EMAT E / FROW=BEG;END FCOL=#;# TROW=1;NOBS TCOL=1;1 
    * Now inspect the residuals with the ARIMA command
 
    ARIMA

ENDO
 
STOP

 

SIGLEVEL= Specifies the significance level for the critical values. Use SIGLEVEL=5 for 5% critical values and use SIGLEVEL=10 (the default) for 10% critical values.
TESTSTAT= Saves the test statistics in the variable specified.
TYPE= Specifies the type of tests to calculate. The available options are:
DF For Dickey-Fuller unit root tests. This is the default.
PP For Phillips-Perron unit root tests.
RESD For Dickey-Fuller tests on the residuals of cointegrating regressions.
RESP For Phillips tests on the residuals of cointegrating regressions.