VAR models have become increasingly popular in recent decades. VAR provides empirical evidence on the response of macroeconomic variables to various exogenous shocks or impulses. Within the framework of a Vector Auto-regressive model (VAR), I want to conduct a robustness test. Specifically, I want to study the impact of policy rate on lending rates and examine the impact of a positive and negative shock on lending rates.
A positive shock (e.g. increase in policy rate) can only allow me to see the impact of a contractionary monetary policy on lending rates. But, I am more interested to look at the impact of a negative shock (e.g. decrease in policy rate or expansionary monetary policy) on lending rates.
So, how to determine the impact of a negative shock via the ‘Impulse Response Function’ using Eviews or other statistical packages?