REGCRITS Procedure |
@REGCRITS is a post-processor for an estimation instruction which computes and (optionally) displays various information criteria. It has no parameters, as it just picks the information off from the accessible variables.
This should be used immediately after any estimation instruction which computes a log likelihood such as LINREG, NLLS, BOXJENK, GARCH, ESTIMATE or MAXIMIZE. However, it can't be applied if you estimated LINREG or NLLS with the INSTRUMENTS option, since instrumental variables/GMM isn't likelihood-based. This uses the value of %LOGL defined by the preceding estimation instruction, and (by default), uses the values of %NOBS for the number of observations and %NFREE for the number of free parameters. Note that %NFREE counts things like the regression variance. The IC's for regression equations usually don't include that (counting only the regressors), because it doesn't matter in comparing two regression equations. It does matter in comparing (say) a regression equation to a GARCH model as the GARCH model explicitly includes parameters for estimating the variance, while the regression concentrates the variance out, but still actually estimates it.
It computes the (standardized forms of the) Akaike Information Criterion, Schwarz Bayesian Criterion, Hannan-Quinn, and FPE. See Information Criteria for details. Their values will look fairly similar. Of course, the key to their use is the comparison across models of a particular criterion. Although these use standardized forms of the criteria and so don't have a strong sensitivity of the number of observations used, it's still considered to be correct procedure to make sure that the competing estimates are done with the same data range.
@REGCRITS( options ) (no parameters)
Options
T=number of observations [%NOBS]
K=number of freely estimated parameters [%NFREE]
[PRINT]/NOPRINT
TITLE="title for report" ["Information Criteria"]
Variables Defined
%AIC |
Akaike (REAL) |
%SBC |
Schwarz Bayesian (REAL) |
%HQCRIT |
Hannan-Quinn (REAL) |
%LOGFPE |
log of the FPE (REAL) |
Example
*
* Verbeek, A Guide to Modern Econometrics, 4th edition
* Illustration 8.8 from pp 311-314
*
open data inflation_extended.txt
calendar(q) 1951:2
data(format=prn,org=columns) 1951:2 2010:04 infl_sa_new
set infl = infl_sa_new
*
* While the data actually start in 1951Q2, all the analysis is set to
* start at 1960Q1.
*
graph(footer="Figure 8.7 Quarterly inflation in the United States, 1960-2010")
# infl 1960:1 *
*
@dfunit(lags=2) infl 1960:1 *
@dfunit(lags=4) infl 1960:1 *
*
* Do KPSS test with up to 12 lags in Newey-West window
*
@kpss(lmax=12) infl 1960:1 *
*
* Do the sample autocorrelations and partial autocorrelations of the
* series.
*
@bjident infl 1960:1 *
*
* In order for the information criteria to be comparable, the estimates
* need to be done over a common range. That's possible here because we
* are fixing the start at 1960:1 even though we have data for many
* years earlier than that.
*
boxjenk(const,ar=3) infl 1960:1 *
@regcrits(title="AR(3) model")
boxjenk(const,ar=4) infl 1960:1 *
@regcrits(title="AR(4) model")
boxjenk(const,ar=3,ma=1) infl 1960:1 *
@regcrits(title="ARMA(3,1) model")
boxjenk(const,ar=6) infl 1960:1 *
@regcrits(title="AR(6) model")
boxjenk(const,ar=||1,2,3,6||) infl 1960:1 *
@regcrits(title="AR(6) with lags 4,5 omitted")
Sample Output
This is the output from the first of the Box-Jenkins instructions from above, followed by the output from the @REGCRITS that follows it. We've also included the @REGCRITS output from a larger AR(6) model. Since you want to minimize the chosen criterion, all the criteria favor of the smaller AR(3), though it's a close call if you're using AIC or FPE.
Box-Jenkins - Estimation by LS Gauss-Newton
Convergence in 3 Iterations. Final criterion was 0.0000000 <= 0.0000100
Dependent Variable INFL
Quarterly Data From 1960:01 To 2010:04
Usable Observations 204
Degrees of Freedom 200
Centered R^2 0.4947772
R-Bar^2 0.4871989
Uncentered R^2 0.7930760
Mean of Dependent Variable 3.9528686302
Std Error of Dependent Variable 3.3003435126
Standard Error of Estimate 2.3633803711
Sum of Squared Residuals 1117.1133557
Regression F(3,200) 65.2883
Significance Level of F 0.0000000
Log Likelihood -462.9026
Durbin-Watson Statistic 1.9651
Q(36-3) 47.3534
Significance Level of Q 0.0504660
Variable Coeff Std Error T-Stat Signif
************************************************************************************
1. CONSTANT 3.9892902356 0.9175027739 4.34799 0.00002187
2. AR{1} 0.2919680365 0.0678154845 4.30533 0.00002610
3. AR{2} 0.2273418840 0.0689302756 3.29814 0.00115192
4. AR{3} 0.3003124483 0.0688887684 4.35938 0.00002085
AR(3) model
AIC 4.587
SBC 4.669
Hannan-Quinn 4.620
(log) FPE 4.587
AR(6) model
AIC 4.588
SBC 4.718
Hannan-Quinn 4.640
(log) FPE 4.588
Copyright © 2025 Thomas A. Doan