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Michael L.
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Heteroscedasticity does not distort your predictive accuarcy but only inference. Therefore, if your aim is just prediction and you do not want to make statements like "$\beta$ is significant" then you do not have to mind about the heteroscedasticity. The technical reason for this is, that you do not need homoscedasticity for consistency or unbiasdeness. Remember that $$\hat{\beta}= \beta +(X'X)^{-1}X'e$$ and therefore $$E[\hat{\beta}]=\beta$$ and $$plim[\hat{\beta}]=\beta$$ if $E[(X'X)^{-1}X'e]=0$ or $plim[(X'X)^{-1}X'e]=0$, respectively. But no assumptions about $V[e|X]$ are needed.

I would recommend you to go with the unbiased estimates and estimate additonally a heteroscedasticity robust variance-covariance matrix (white-huber standard errors) of the style $ (X'X)^{-1}X'ee'X(X'X)^{-1}$ but I would not recommend to use FGLS (which includes weighted least squares) for prediction as the FGLSE (feasible generalized least squares estimator) is biased.

Heteroscedasticity does not distort your predictive accuarcy but only inference. Therefore, if your aim is just prediction and you do not want to make statements like "$\beta$ is significant" then you do not have to mind about the heteroscedasticity. The technical reason for this is, that you do not need homoscedasticity for consistency or unbiasdeness. Remember that $$\hat{\beta}= \beta +(X'X)^{-1}X'e$$ and therefore $$E[\hat{\beta}]=\beta$$ and $$plim[\hat{\beta}]=\beta$$ if $E[(X'X)^{-1}X'e]=0$ or $plim[(X'X)^{-1}X'e]=0$, respectively. But no assumptions about $V[e|X]$ are needed.

Heteroscedasticity does not distort your predictive accuarcy but only inference. Therefore, if your aim is just prediction and you do not want to make statements like "$\beta$ is significant" then you do not have to mind about the heteroscedasticity. The technical reason for this is, that you do not need homoscedasticity for consistency or unbiasdeness. Remember that $$\hat{\beta}= \beta +(X'X)^{-1}X'e$$ and therefore $$E[\hat{\beta}]=\beta$$ and $$plim[\hat{\beta}]=\beta$$ if $E[(X'X)^{-1}X'e]=0$ or $plim[(X'X)^{-1}X'e]=0$, respectively. But no assumptions about $V[e|X]$ are needed.

I would recommend you to go with the unbiased estimates and estimate additonally a heteroscedasticity robust variance-covariance matrix (white-huber standard errors) of the style $ (X'X)^{-1}X'ee'X(X'X)^{-1}$ but I would not recommend to use FGLS (which includes weighted least squares) for prediction as the FGLSE (feasible generalized least squares estimator) is biased.

Source Link
Michael L.
  • 1.5k
  • 10
  • 17

Heteroscedasticity does not distort your predictive accuarcy but only inference. Therefore, if your aim is just prediction and you do not want to make statements like "$\beta$ is significant" then you do not have to mind about the heteroscedasticity. The technical reason for this is, that you do not need homoscedasticity for consistency or unbiasdeness. Remember that $$\hat{\beta}= \beta +(X'X)^{-1}X'e$$ and therefore $$E[\hat{\beta}]=\beta$$ and $$plim[\hat{\beta}]=\beta$$ if $E[(X'X)^{-1}X'e]=0$ or $plim[(X'X)^{-1}X'e]=0$, respectively. But no assumptions about $V[e|X]$ are needed.