rndseed 128 'set the random seed
wfcreate q 1989 2020 'make quarterly workfile with 128 quarter

series eps = 8*(@quarter=1) + @rnorm 'create random normal innovations with each first quarter having mean 8
series x 'create a series x
x(1) = @rnorm 'set the first observation to a random normal value

smpl 1989q2 @last 'start the sample at the 2nd quarter
x =  0.75*x(-1) + eps 'generate an AR process using eps as innovations

smpl @all 'reset the sample to the full workfile range