[R] regress postestimation -- Postestimation tools for regress
Description
The following postestimation commands are of special interest after regress:
Command Description
-------------------------------------------------------------------------------------------------------
dfbeta DFBETA influence statistics
estat hettest tests for heteroskedasticity
estat imtest information matrix test
estat ovtest Ramsey regression specification-error test for omitted variables
estat szroeter Szroeter's rank test for heteroskedasticity
estat vif variance inflation factors for the independent variables
estat esize eta-squared and omega-squared effect sizes
Syntax for estat imtest
estat imtest [, preserve white]
Menu for estat
Statistics > Postestimation > Reports and statistics
Description for estat imtest
estat imtest performs an information matrix test for the regression model and an orthogonal
decomposition into tests for heteroskedasticity, skewness, and kurtosis due to Cameron and Trivedi
(1990); White's test for homoskedasticity against unrestricted forms of heteroskedasticity (1980) is
available as an option. White's test is usually similar to the first term of the Cameron-Trivedi
decomposition.
Options for estat imtest
preserve specifies that the data in memory be preserved, all variables and cases that are not needed in
the calculations be dropped, and at the conclusion the original data be restored. This option is
costly for large datasets. However, because estat imtest has to perform an auxiliary regression on
k(k+1)/2 temporary variables, where k is the number of regressors, it may not be able to perform
the test otherwise.
white specifies that White's original heteroskedasticity test also be performed.