Hi, Thank you for your prompt response. They asked students to use Newey-west, which I think is what Gretl uses for time series HAC. I've seen it in Stata, the student was told by the supervisor to use Eviews. I was hoping there was a way around as using robust statistics I still get a low Durbin Watson. The supervisor didn't want them to dynamic panel regression Thank you Alison Sent from Outlook for Android<https://aka.ms/AAb9ysg> ________________________________ From: Sven Schreiber <sven.schreiber(a)fu-berlin.de&gt; Sent: Wednesday, September 6, 2023 11:20:23 AM To: gretl-users(a)gretlml.univpm.it <gretl-users(a)gretlml.univpm.it&gt; Subject: [EXTERNAL] [Gretl-users] Re: panel regression HAC *** CAUTION - EXTERNAL EMAIL. Think before replying, opening attachments, or clicking any links. If in doubt, please forward to phishing@northampton.ac.uk<mailto:phishing@northampton.ac.uk> or click ‘Report Phishing’ button. *** Am 06.09.2023 um 11:05 schrieb Alison Loddick: Hi, If we have time series data, we can use HAC robust standard errors; however, with panel regression, the robust standard errors are Arellano or PCSE. Is there a way using programming that we can do HAC for panel regression? From what I have read, Arellano isn't as good at dealing with serial correlation. Although I'm aware we can do dynamic panel regression, I'm fighting with lecturers who want students to use Eviews because you can use HAC for panel regression there. Hi Alison, thanks for fighting on behalf of gretl! As mentioned in section 22.4 of the user guide, the Arellano cov estimator for panel data can be seen as HAC (at least for small T), and it says that an alternative denomination would be “clustered (over entities)”. Actually, I'm looking at the Eviews program (13) and their help files to check out the situation there right now. There's no explicit mention of HAC in the panel options, but you have "period cluster", "cross-section cluster", and "two-way cluster" (all combined with the "White" name). So it looks like gretl's "Arellano" option is conceptually the same as Eviews's "White period (cross-section cluster)". What do your colleagues mean exactly when they say they use HAC for panel regression? It's not obvious. A related way of looking at this issue is that gretl's native panel tools do not handle cross-sectional dependence (CSD, contemporaneous error correlation). From your description it sounds as if the time-dimension (within) correlation is all you want to take into account or allow, and then you're good to go with core gretl. If, however, you also worry (or want to teach) CSD, then I would point you to the "CSDpanel" contributed function package written by Jörg Breitung and myself, currently at version 0.2 from three years ago. Among some other tools, we offer the two-way clustered standard errors suggested by Driscoll and Kraay (1998). (I guess this should correspond to Eviews's two-way cluster option, but I don't know why they don't mention the names of Driscoll/Kraay or whether there are any other subtleties.) So it seems that the only option we don't have available in the gretl ecosystem is "White cross-section (period cluster)". Not sure how relevant that is. Everybody is welcome to correct me if I'm misinterpreting something in this area. cheers sven University of Northampton: Transforming Lives and Inspiring Change www.northampton.ac.uk This e-mail is private and may be confidential and is for the intended recipient only. If you are not the intended recipient you are strictly prohibited from using, printing, copying, distributing or disseminating this e-mail or any information contained in it. We virus scan all E-mails leaving The University of Northampton but no warranty is given that this E-mail and any attachments are virus free. You should undertake your own virus checking. The right to monitor E-mail communications through our networks is reserved by us. Disclaimer The information contained in this communication from the sender is confidential. It is intended solely for use by the recipient and others authorized to receive it. If you are not the recipient, you are hereby notified that any disclosure, copying, distribution or taking action in relation of the contents of this information is strictly prohibited and may be unlawful. This email has been scanned for viruses and malware, and may have been automatically archived by Mimecast, a leader in email security and cyber resilience. Mimecast integrates email defenses with brand protection, security awareness training, web security, compliance and other essential capabilities. Mimecast helps protect large and small organizations from malicious activity, human error and technology failure; and to lead the movement toward building a more resilient world. To find out more, visit our website.

Hi Sven, I've just had a look at the Stata manual and it looks like Newey West is only available for old panel regression. They use cluster approach for fixed and random effects. I think I have enough to go back with a convincing argument. Thank you Alison Sent from Outlook for Android<https://aka.ms/AAb9ysg> ________________________________ From: Alison Loddick <Alison.Loddick(a)northampton.ac.uk&gt; Sent: Wednesday, September 6, 2023 11:29:39 AM To: Gretl list <gretl-users(a)gretlml.univpm.it&gt; Subject: Re: [EXTERNAL] [Gretl-users] Re: panel regression HAC Hi, Thank you for your prompt response. They asked students to use Newey-west, which I think is what Gretl uses for time series HAC. I've seen it in Stata, the student was told by the supervisor to use Eviews. I was hoping there was a way around as using robust statistics I still get a low Durbin Watson. The supervisor didn't want them to dynamic panel regression Thank you Alison Sent from Outlook for Android<https://aka.ms/AAb9ysg> ________________________________ From: Sven Schreiber <sven.schreiber(a)fu-berlin.de&gt; Sent: Wednesday, September 6, 2023 11:20:23 AM To: gretl-users(a)gretlml.univpm.it <gretl-users(a)gretlml.univpm.it&gt; Subject: [EXTERNAL] [Gretl-users] Re: panel regression HAC *** CAUTION - EXTERNAL EMAIL. Think before replying, opening attachments, or clicking any links. If in doubt, please forward to phishing@northampton.ac.uk<mailto:phishing@northampton.ac.uk> or click ‘Report Phishing’ button. *** Am 06.09.2023 um 11:05 schrieb Alison Loddick: Hi, If we have time series data, we can use HAC robust standard errors; however, with panel regression, the robust standard errors are Arellano or PCSE. Is there a way using programming that we can do HAC for panel regression? From what I have read, Arellano isn't as good at dealing with serial correlation. Although I'm aware we can do dynamic panel regression, I'm fighting with lecturers who want students to use Eviews because you can use HAC for panel regression there. Hi Alison, thanks for fighting on behalf of gretl! As mentioned in section 22.4 of the user guide, the Arellano cov estimator for panel data can be seen as HAC (at least for small T), and it says that an alternative denomination would be “clustered (over entities)”. Actually, I'm looking at the Eviews program (13) and their help files to check out the situation there right now. There's no explicit mention of HAC in the panel options, but you have "period cluster", "cross-section cluster", and "two-way cluster" (all combined with the "White" name). So it looks like gretl's "Arellano" option is conceptually the same as Eviews's "White period (cross-section cluster)". What do your colleagues mean exactly when they say they use HAC for panel regression? It's not obvious. A related way of looking at this issue is that gretl's native panel tools do not handle cross-sectional dependence (CSD, contemporaneous error correlation). From your description it sounds as if the time-dimension (within) correlation is all you want to take into account or allow, and then you're good to go with core gretl. If, however, you also worry (or want to teach) CSD, then I would point you to the "CSDpanel" contributed function package written by Jörg Breitung and myself, currently at version 0.2 from three years ago. Among some other tools, we offer the two-way clustered standard errors suggested by Driscoll and Kraay (1998). (I guess this should correspond to Eviews's two-way cluster option, but I don't know why they don't mention the names of Driscoll/Kraay or whether there are any other subtleties.) So it seems that the only option we don't have available in the gretl ecosystem is "White cross-section (period cluster)". Not sure how relevant that is. Everybody is welcome to correct me if I'm misinterpreting something in this area. cheers sven University of Northampton: Transforming Lives and Inspiring Change www.northampton.ac.uk This e-mail is private and may be confidential and is for the intended recipient only. If you are not the intended recipient you are strictly prohibited from using, printing, copying, distributing or disseminating this e-mail or any information contained in it. We virus scan all E-mails leaving The University of Northampton but no warranty is given that this E-mail and any attachments are virus free. You should undertake your own virus checking. The right to monitor E-mail communications through our networks is reserved by us. Disclaimer The information contained in this communication from the sender is confidential. It is intended solely for use by the recipient and others authorized to receive it. If you are not the recipient, you are hereby notified that any disclosure, copying, distribution or taking action in relation of the contents of this information is strictly prohibited and may be unlawful. This email has been scanned for viruses and malware, and may have been automatically archived by Mimecast, a leader in email security and cyber resilience. Mimecast integrates email defenses with brand protection, security awareness training, web security, compliance and other essential capabilities. Mimecast helps protect large and small organizations from malicious activity, human error and technology failure; and to lead the movement toward building a more resilient world. To find out more, visit our website.