Is a time series has a mean reversion level >=0 is it automatically covariance stationary? thanks!
Not neccesarily I would think- since mean revesion is B0/(1-B1) you could have a B1 that is 1.001 (which is significantly not different from 1) and a B0 which is, well, anything.
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Cheers serf dude I see what you’re saying.
for an AR model to be covariance stationary it must be less than 0 if b1 is equal to zero , there is unit root