Null Hypothesis: Unit root (individual unit root process)  
Series: D(FREQ) 
 
Date: 03/28/16 Time: 09:33 
 
Sample: 1 144 

 
Exogenous variables: Individual effects  
NeweyWest automatic bandwidth selection and Bartlett kernel  
Total (balanced) observations: 140  
Crosssections included: 2 
 
Method  Statistic  Prob.^{**}  
PPFisher Chisquare  49.4345  0.0000  
PPChoi Zstat  −6.22505  0.0000  
^{**}Probabilities for Fisher tests are computed using an  
asymptotic Chisquare distribution. All other tests  
assume asymptotic normality.  
Intermediate PhillipsPerron test results D(FREQ)  
Cross 



section  Prob.  Bandwidth  Obs 
FFV  0.0000  4.0  70 
JLX  0.0001  1.0  70 