Object Reference : Object View and Procedure Reference : Var
  
 
hdecomp
Performs graph of historical decomposition for a standard VAR.
Syntax
var_name.hdecomp(n, options) [ser1 ser2 ser3 ...] [@ component_series [@ ordering_series]]
List the series names in the Var you would like to decompose in the order you wish to display the graphs. If you do not specify series, all of the series in the Var will be employed. You may optionally specify the component series by listing the series after an “@” and, if you are using Cholesky weighting for the decomposition, you may change the ordering by listing the order of the series after a second “@”.
By default, EViews computes the decomposition of only the stochastic component into all components using the ordering in the Var. You may instead elect to include the baseline in the decomposition.
Options
 
m (default)
Display multiple graphs, with the impact of each component on a dependent variable shown in a separate graphs.
g
Display combined graphs, with decomposition of each variable with respect to all included components shown in one graph.
imp=arg (default=“chol”)
Type of factorization for the decomposition: unit impulses, ignoring correlations among the residuals (“imp=unit”), non-orthogonal, ignoring correlations among the residuals (“imp=nonort”), Cholesky with d.f. correction (“imp=chol”), Cholesky without d.f. correction (“imp=mlechol”), Generalized (“imp=gen”), structural (“imp=struct”), or user specified (“imp=user”).
The structural factorization is based on the estimated structural VAR. To use this option, you must first estimate the structural decomposition; see Var::svar.
For user-specified weights, you must specify the name of the vector/matrix containing the impulses using the “fname=” option.
baseline
Include the baseline in the decomposition.
start= date
Start date (within estimation sample) for the decomposition. By default, EViews uses the first date of the estimation sample.
end = date
End date (within estimation sample) for the decomposition. By default, EViews uses the last date of the estimation sample.
basename=arg
Optional name fragment used in constructing the names for the series in which to save the decomposition results. If the basename is “base,” the total stochastic or stochastic plus baseline will be saved in the series BASE1, BASE2, etc... (where the numbers in the name correspond to the ordering of the variables in the VAR specification). The components will be saved in the series BASE1_1, BASE1_2, …, BASE2_1, BASE2_2, …., where the numbers after the “_” refer to the ordering of the series in the VAR. Series will be saved only for those variables and components requested above.
n=arg
Optional name of group object to contain the series created using the "basename=" option.
prompt
Force the dialog to appear from within a program.
p
Print the results.
Examples
var var1.ls 1 4 m1 gdp cpi
var1.hdecomp(10, baseline, m) gdp @ m1 gdp cpi
The first line declares and estimates a VAR with three variables. The second line displays multiple graphs of the historical decomposition of GDP to shocks to the three series in the VAR using the ordering as specified in VAR1. The baseline will be included in the graph.
Cross-references
See “Vector Autoregression (VAR) Models” for a discussion of historical decomposition in VARs.