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  • Backward Selection with Newey-West standard errors

    Hello,

    Im using an OLS regression and have decided to use the backward selection method.

    Im not really sure how to conduct the backward selection if i have autocorrelation & heteroskedasticity and use Newey-West.

    Should i first runt the regression --> Test BG/BP --> Run Newey-West. and then remove the least significant varaible. Then start over, run the regression again with out the variable that was least significant --> Run "estat ic" to see if AIC/BIC decreased or if asjusted R^2 increased.

  • #2
    Cross-posted at https://stats.stackexchange.com/ques...y-west-standar

    Please note our longstanding request in the FAQ to tell us about cross-posting. That is good etiquette in any forum.

    Comment


    • #3
      The regular Stata command for stepwise selection is stepwise. However, this does not work with newey. Since I am not finding a suitable dataset to run with command at all in your setting, maybe you can just try this ado:
      Code:
      ssc install gvselect, replace
      help gvselect
      Best wishes

      Stata 18.0 MP | ORCID | Google Scholar

      Comment


      • #4
        I had not heard of gvselect (SSC) before, so I looked at the description.

        Code:
        . ssc describe gvselect
        
        -----------------------------------------------------------------------------------------------
        package gvselect from http://fmwww.bc.edu/repec/bocode/g
        -----------------------------------------------------------------------------------------------
        
        TITLE
              'GVSELECT': module to perform best subsets variable selection
        
        DESCRIPTION/AUTHOR(S)
              
               gvselect performs best subsets variable selection.  The
              Furnival-Wilson (Technometrics, 1974) leaps-and-bounds algorithm
              is applied using the log likelihoods of candidate models,
              allowing variable selection to be performed on a wide family of
              normal and non-normal regression models.  This method is
              described in Lawless and Singhal (Biometrics, 1978). The log
              likelihood, Akaike's information criterion, and the Bayesian
              information criterion are reported for the best regressions at
              each predictor quantity.
              
        --- snip the rest ---

        In the Stata FAQ on stepwise regression, both Frank Harrell and Ronán Conroy state that "all possible subsets" regression does not address any of the well-known problems with stepwise regression. I'm curious to know how the method(s) used in -gvselect- (SSC) address those concerns. Thanks.
        --
        Bruce Weaver
        Email: [email protected]
        Version: Stata/MP 19.5 (Windows)
        Crypticity belongs in crosswords, not code! 🤨

        Comment


        • #5
          I assume that gvselect does not solve these problems at all, it is just an alternative to stepwise. Also: the problems mentioned concern theory building / testing but there might be other uses for stepwise regressions (maybe prediction?), so there are probably some applications where it can be useful.
          EDIT: there is apparently more information available here: https://journals.sagepub.com/doi/pdf...867X1501500406
          Best wishes

          Stata 18.0 MP | ORCID | Google Scholar

          Comment

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