jacksparrow

I believe a unit root refers specifically to the coefficient in a time series (b1). If the coefficient is not statistically significant from 1, then it has a unit root. Random walks describe the dependent variable, which is equal to the value of the dependent value in the previous period plus an error term. So basically, a random walk has a unit root because the coefficient's mean reverting level (bo/(1-b1)) is undefined.

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