Could someone explain to me the last bit of the ARMAX output? I would think it means that there's a unit root (or explosive), but when I run an augmented dickey-fuller test, it says no unit root...thanks! Model 1: ARMAX, using observations 1957:06-1979:08 (T = 267) Estimated using Kalman filter (exact ML) Dependent variable: Ratio Standard errors based on Hessian coefficient std. error z p-value --------------------------------------------------------- const 0.650441 0.0246480 26.39 1.83e-153 *** phi_1 0.876993 0.0297168 29.51 2.04e-191 *** var23 0.00235627 0.000457168 5.154 2.55e-07 *** Mean dependent var 0.735553 S.D. dependent var 0.083849 Mean of innovations -0.000334 S.D. of innovations 0.035214 Log-likelihood 513.8762 Akaike criterion -1019.752 Schwarz criterion -1005.403 Hannan-Quinn -1013.989 Real Imaginary Modulus Frequency ----------------------------------------------------------- AR Root 1 1.1403 0.0000 1.1403 0.0000 -----------------------------------------------------------