what is the function of root testing for endogenous variables which exogenous variable is used in unit root testing do we run unit roots of variables which variables does unit root testing for can cointegration run on exogenous variables? when do you do unit root testing for exogenous variables which variable does unit root test for do i need to test exogenous variables in unit root test do i need to run unit root test on endogenous variable are vecm and cointegration exogenous what does unit root testing for exogenous variables check what is unit root testing what is unit root testing when running cointegration do i have to run unit root test for exogenous variable what is unit root testing for exogenous variables is cointegration a unit root test what is unit root testing for exogenous variables what is unit root testing for exogenous variables do you run unit root tests for exogenous variables? what variables does unit root test work on