各位大神谁能帮忙讲讲2和4题 感激不尽


2.Do we need recent data to generate Impulse response function (IRF) and variancedecomposition (VD)? Or the estimated coefficients from VAR or VECM are sufficient?Can we say that variance decomposition is better than impulse response for the purposeof studying the relationship between the endogenous variables? Discuss pros and cons ofIRF and VD.

4 Is the cholesky decomposition the most appropriate method to identify structural shocksin VAR model? Discuss the pros and cons of all the alternative approaches.