12.3 Detecting Autocorrelation Because the true u are unobservable. we have to rely on the es obtained from the standard ols procedure to learnsomething about the presence, or lack thereof, of autocorrelation12.3 Detecting Autocorrelation Because the true ui are unobservable, we have to rely on the et s obtained from the standard OLS procedure to “learn”something about the presence, or lack thereof, of autocorrelation