https://communities.sas.com/t5/SAS-Forecasting-and-Econometrics/DIckey-Fuller-interpretation/m-p/357310#M2334 <P>Hi Sizzen,</P> <P>&nbsp;</P> <P>For the table provided of Dickey-Fuller test results on your first-differenced series, all 3 p-values shown in the Pr &lt; Tau column are smaller than the alpha-level you mentioned of 0.05.&nbsp; This causes you to reject the null hypothesis that the series has a unit root and conclude that no further differencing is needed.</P> <P>&nbsp;</P> <P>I hope this helps!</P> Tue, 09 May 2017 21:30:40 GMT dw_sas 2017-05-09T21:30:40Z https://communities.sas.com/t5/SAS-Forecasting-and-Econometrics/DIckey-Fuller-interpretation/m-p/356930#M2322 <DIV><IMG src="https://communities.sas.com/t5/image/serverpage/image-id/8762i953278793E277D63/image-size/original?v=1.0&amp;px=-1" border="0" alt="kl.PNG" title="kl.PNG" /></DIV><P>&nbsp;</P><P>I have time series, and after 1st difference i got this .</P><P>&nbsp;Pr&lt;Tau in first and second row is &lt;0,05, but in third line it is &gt;0,05.</P><P>So what i have to do ? It is stationary or i have to do second difference ?</P> Mon, 08 May 2017 16:42:11 GMT https://communities.sas.com/t5/SAS-Forecasting-and-Econometrics/DIckey-Fuller-interpretation/m-p/356930#M2322 Sizzen 2017-05-08T16:42:11Z https://communities.sas.com/t5/SAS-Forecasting-and-Econometrics/DIckey-Fuller-interpretation/m-p/357310#M2334 <P>Hi Sizzen,</P> <P>&nbsp;</P> <P>For the table provided of Dickey-Fuller test results on your first-differenced series, all 3 p-values shown in the Pr &lt; Tau column are smaller than the alpha-level you mentioned of 0.05.&nbsp; This causes you to reject the null hypothesis that the series has a unit root and conclude that no further differencing is needed.</P> <P>&nbsp;</P> <P>I hope this helps!</P> Tue, 09 May 2017 21:30:40 GMT https://communities.sas.com/t5/SAS-Forecasting-and-Econometrics/DIckey-Fuller-interpretation/m-p/357310#M2334 dw_sas 2017-05-09T21:30:40Z