can i run a var and a vec on each variable what is the difference between var and vac in statistics if variables need to be cointegrated are they all allowed to exist in the model? why do you have to model nonstationary variables can we model nonstationary variables if a variable is cointegrated in levels does this mean a difference of a var and a cec can a non-stationary variable be modelled as one cointegrated variable do non-stationary variables require cointegration can a non-stationary variable be modelled only if they are cointegrated to each other how many cointegration vectors are necessary for the johansen test can i model variables in level using a var what is the difference between var and volc what is a var / vec can you model a variable in a level by a voc? what variables does a vol/vec test test for what is a var or cec level why do variables have to be cointegrated how many vectors in a var/sec what is the difference between a var & a nec is it valid to do a var in multiple variables