[R-sig-Geo] Shiny app for Spatial Econometric classes
Roger Bivand
Roger@B|v@nd @end|ng |rom nhh@no
Mon Jul 12 11:16:16 CEST 2021
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 abraço,
>>
>> Raphael Saldanha
>>
>>> Em 8 de jul. de 2021, à(s) 08:45, Spencer Graves
>>> <spencer.graves using 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, à(s) 23:20, Rolf Turner <r.turner using auckland.ac.nz>
>>>>> escreveu:
>>>>>
>>>>>
>>>>>> On Wed, 7 Jul 2021 18:09:50 -0300
>>>>>> Raphael Saldanha <rfsaldanha using 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
>>>>>
>>>>> _______________________________________________
>>>>> R-sig-Geo mailing list
>>>>> R-sig-Geo using r-project.org
>>>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>>> _______________________________________________
>>>> R-sig-Geo mailing list
>>>> R-sig-Geo using r-project.org
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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 using nhh.no
https://orcid.org/0000-0003-2392-6140
https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en
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