Shiny app for Spatial Econometric classes
Perhaps it is just my connection, but it is not possible to load any data, so I cannot evaluate the other components in practice. I do however think that you need to acknowledge the results of Piras and Prucha, https://doi.org/10.1016/j.regsciurbeco.2014.03.002, and try to point out the dangers of pre-testing, rather than estimating the most inclusive model first, and simplifying from there. Roger
On Fri, 9 Jul 2021, Roger Bivand wrote:
Returning to the "Tobler" shiny app: The main serious weakness is the name and the approach. It is not and has never been the case that "Everything is related to everything else, but near things are more related than distant things." This is and has always been an oversimplification, disguising the underlying entitation/support problem. Are the units of observation appropriate for the scale of the unobserved spatial process? Tobler (1970) https://doi.org/10.2307/143141 was published in the same SI as Olsson (1970) https://doi.org/10.2307/143140 (Olsson precedes Tobler), but Olsson does grasp the important point that spatial autocorrelation is not immanent in spatial phenomena, but often is engendered by inappropriate entitation, by omitted variables and/or inappropriate functional form. The key quote from Olsson is on p. 228: "The existence of such autocorrelations makes it tempting to agree with Tobler (1970, 236 [my interpolation, the original refers to a conference paper]) that 'everything is related to everything else, but near things are more related than distant things.' On the other hand, the fact that the autocorrelations seem to hide systematic specification errors suggests that the elevation of this statement to the status of 'the first law of geography' is at best premature. At worst, the statement may represent the spatial variant of the post hoc fallacy, which would mean that coinincidence has been mistaken for a causal relation." The status of the "first law" is very similar to the belief that John Snow induced the cause of cholera as water-borne from a map. It may be a good way of selling GIS, but it isn't accurate; Snow had a strong working microbiological hypothesis prior to visiting Soho, and the map was prepared after the Broad street pump was disabled as documentation that the hypothesis held (see https://doi.org/10.1016/s0140-6736(00)02442-9 Brody et al. 2000). So the framing of the shiny app is unfortunate, and spatial econometrics is not a toolbox, rather a way of loooking at mis-specification when space is involved, I think. Hope this isn't too critical, Roger On Thu, 8 Jul 2021, Raphael Saldanha wrote:
Estimado Spencer, Thanks for your kind words. Actually, that construction is not standard in Portuguese also (although that does not sound pedant or with some bad intention for our ears). I revised the text three times and used an app for grammar correction before sending. Anyway, it was a mistake by all means. To learn Spatial Econometrics and other fields require from us additional efforts. There is just a few books or materials in Portuguese. But I try to approach this difficult as an opportunity to learn. Indeed, one of the reasons for building the app was to facilitate the use of the methods for people that are learning R. *Professor Eduardo and I* teach annually a course on that field and we face this challenge. With the pandemics and Zoom classes, we hope that the app and our scripts will help the students to learn R. Um forte abra?o, Raphael Saldanha
Em 8 de jul. de 2021, ?(s) 08:45, Spencer Graves
<spencer.graves at prodsyse.com> escreveu:
Estimado Raphael:
I don't know any Portuguese either, and I'm very grateful that you've
made the effort to ask this group in a language not your own.
In primary school, I learned that constructions like, "Me and
Professor ..." too often sounded like, "Mean Professor ...".
Un fuerte abrazo ("A big hug", as a Uruguayan man whom I had not
previously met ended a letter inviting me to talk at a conference).
Spencer Graves
On 7/8/21 5:32 AM, Raphael Saldanha wrote:
No offense taken. Thanks for the remark and opportunity to learn. Cheers, Raphael
Em 7 de jul. de 2021, ?(s) 23:20, Rolf Turner <r.turner at auckland.ac.nz> escreveu:
On Wed, 7 Jul 2021 18:09:50 -0300 Raphael Saldanha <rfsaldanha at gmail.com> wrote: Hello all! Me and Professor Eduardo Almeida (UFJF, Brazil) are creating an R Shiny app for Spatial Econometric classes.
<SNIP> I hope that you won't find this comment offensive, but I could not resist sending it to you, since I am rather fanatical (pedantic?) about correct English usage. The expression "Me and Professor Eduardo Almeida" is both (a) bad grammar and (b) bad form. (a) Instead of the pronoun "Me" (accusative or objective case) you should use "I" (nominative or subjective case), since this expression is the subject of the sentence. (b) It is "bad form" (it sounds vaguely self-promoting) to put a first person pronoun before the names of others to which it is linked. You should say "Professor Eduardo Almeida and I are creating ....". I realise that English is surely a second language for you, and your English is infinitely better than my non-existent Portuguese. Your English is actually quite good, probably better than that of many native English speakers. Nevertheless the expression that you use is not correct and you should strive to avoid such usage. Again let me express the hope that you won't take offence at this comment. cheers, Rolf Turner -- Honorary Research Fellow Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276
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Roger Bivand Emeritus Professor Department of Economics, Norwegian School of Economics, Postboks 3490 Ytre Sandviken, 5045 Bergen, Norway. e-mail: Roger.Bivand at nhh.no https://orcid.org/0000-0003-2392-6140 https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en