Lag Exclusion test for VAR - What are the null and alternative hypotheses?

everyone.

I ran a lag exclusion test for my VAR model on EViews and arrived at the Chi-squared test statistics as shown in the image linked below. Could someone please tell me what exactly are the null and alternative hypotheses for the individual and joint tests being used here and how should I decide which of these should I use, the individual or the joint test? Also, how can I find which lags are insignificant and how should I proceed to remove them from my model?

Best,

Max

• Isn't the $H_0$ that the coefficient for a particular variable (or all variables jointly) at a particular lag equals zero? Thus the test would be not about lag length but rather about the inclusion/exclusion of a particular lag in this VAR(4) model? – Richard Hardy Dec 23 '18 at 20:23