Stationarity Suppose y, follows an AR(1) process without drift Is y stationarity? ◆ Note that y=的y1=1+E 的(y,如1)+、85x +E11+的E12+3 +外y 1212 Stationarity  Suppose yt follows an AR(1) process without drift.  Is yt stationarity?  Note that o t t t t t t t t t t t y y y y 3 1 3 2 1 2 1 1 1 1 1 2 1 1 1 ........... ( )               = + + + + + = + + = + − − − − − −