[R-sig-Geo] SLX model for splm package in R
dfamaral at usp.br
dfamaral at usp.br
Tue Aug 30 04:09:05 CEST 2016
Dear all,
Impacts in SLX model are calculated directly by parameters estimation:
http://onlinelibrary.wiley.com/doi/10.1111/jors.12188/abstract
Beta1 gives direct impact and Beta 2 the indirect:
y = beta1*X + beta2*WX + e
I understand W must multiply T times the X matrix (T is the lenght of time series for a panel data). And variables are demeaned after WX is calculated.
Daniel.
----- Mensagem original -----
De: "Roger Bivand" <Roger.Bivand at nhh.no>
Para: "Burcu Ozuduru" <bozuduru at gmail.com>
Cc: dfamaral at usp.br, r-sig-geo at r-project.org
Enviadas: Segunda-feira, 29 de Agosto de 2016 4:13:26
Assunto: Re: [R-sig-Geo] SLX model for splm package in R
This is far too ad-hoc a discussion. For Spatial panel SLX, please read
carefully:
http://dx.doi.org/10.1016/j.spasta.2014.02.002
DOI 10.1007/s10109-015-0217-3
DOI: 10.1111/jors.12188
for a view of the state of play. One question - should you demean the X
variables before taking spatial lags? This does not apply to cross-section
models for which spdep::create_WX() was written, for obvious reasons. A
second question - how do you handle the calculation of total impacts in
this setting? In cross-section models, this is reasonably easy, by linear
combination. But in spatial panel SLX models, is it easy? What does the
literature suggest?
On Mon, 29 Aug 2016, Burcu Ozuduru wrote:
> Hi,
>
> This is a great question because I faced the same problem a while back.
> What I did is to obtain the spatial weight matrix as (have spdep
> installed).
>
> S47matrix<-W1%*%S47
>
> and then put it in my data frame and equation. Btw, above W1 is a spatial
> weights matrix I obtained from a neighbor list
> (W1=as.matrix(as_dgRMatrix_listw(ccListw))) and S47 is the dependent
> variable.
>
> m2<-data.frame(S41,S46,S47,S65,S68,S47matrix,MAD10000,NQPDA10000,TPBtA10000,DivA10000,Lnk10000)
> summary(m2<-zeroinfl(S47~MAD10000+NQPDA10000+S47matrix, dist="negbin"))
>
> I also wanted to ask whether I was on the right track. Professor Bivand, if
> this is a common problem could you direct us to a relevant page -if
> available and if at all possible- please? Your advice would be sincerely
> appreciated.
This is an inappropriate question for this thread (SLX spatial panel
models). You must refer to the literature, and understand what you are
doing:
zeroinfl(S47~MAD10000+NQPDA10000+S47matrix, dist="negbin")
is completely wrong, as S47matrix is Wy, the spatial lag of the dependent
variable, and this spatial lag model of response S47 cannot be estimated
using pscl::zeroinfl (do say which package provides the functions you
mention). Your only recourse is to write your own Bayesian model. It is
even extremely likely that this model doesn't make any substantive sense,
unless you have a good understanding about why S47 at i (for all i) should
be simultaneously caused by the full set of values of S47. A model in the
error might make sense (a zero inflated negbin model with an additive mrf
random effect (maybe R2BayesX 10.18637/jss.v014.i11).
An SLX zero inflated negbin model could maybe apply, in which case
pscl::zeroinfl might be applicable, but then you'd be including the lags
of MAD10000 and NQPDA10000, not the response, and inference on total
impacts of these variables could be challenging rather than obvious (MCMC
summaries of the summed samples of the coefficients would work, but here
no MCMC I think - R2BayesX might help).
Most of these issues are far more complex than students or their
supervisors understand, do ask an experienced applied statistician (I'm
not an applied statistician, don't rely on my suggestions, you yourself
are responsible for your results).
Hope this clarifies,
Roger
>
> Kind Regards-
>
> Thanks-
>
> Burcu
>
> ---
>
> Burcu H. Ozuduru,
> Gazi University, Faculty of Architecture,
> Department of City and Regional Planning
> Maltepe-Ankara Turkey
> t: +90-312-5823701
> e: bozuduru at gazi.edu.tr
> http://websitem.gazi.edu.tr/bozuduru
>
>
> On Mon, Aug 29, 2016 at 12:42 AM, Roger Bivand <Roger.Bivand at nhh.no> wrote:
>
>> On Sun, 28 Aug 2016, dfamaral at usp.br wrote:
>>
>> Dear colleagues,
>>>
>>> Does anyone know how to implement Spatial Lag of X (SLX) model for panel
>>> data using splm package? I tried the following to create a WX matrix and
>>> then apply Fixed and Random Effects:
>>>
>>> tb <- read.csv2("panel.csv", header = TRUE, sep = ";", dec = ".")
>>> time <- length(unique(tb$year))
>>> X <- as.matrix(tb[ ,3:20])
>>>
>>
>> class(X) is not "pseries", is it?
>>
>> WX <- slag(X, listw, maxlag = 1)
>>>
>>> I see that slag is applicable for vectors of pseries, but this command
>>> led to the error message: "Error in UseMethod("slag"): no applicable method
>>> for 'slag' applied to an object of class "c('matrix', 'double', 'numeric')"
>>>
>>
>> slag.default() takes a vector, slag.pseries() a "pseries" object.
>>
>>
>>> Is there any way to implement this SLX model for panel series?
>>>
>>
>> Did you look at spdep::create_WX?
>>
>>
>>> Regards,
>>>
>>> Daniel.
>>>
>>> [[alternative HTML version deleted]]
>>>
>>>
>> Please do not post HTML - like insects, HTML carries infectious payloads
>> and wastes bandwidth and server processing capacity.
>>
>> _______________________________________________
>>> R-sig-Geo mailing list
>>> R-sig-Geo at r-project.org
>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>>
>>>
>> --
>> Roger Bivand
>> Department of Economics, Norwegian School of Economics,
>> Helleveien 30, N-5045 Bergen, Norway.
>> voice: +47 55 95 93 55; fax +47 55 95 91 00
>> e-mail: Roger.Bivand at nhh.no
>> http://orcid.org/0000-0003-2392-6140
>> https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en
>> http://depsy.org/person/434412
>>
>> _______________________________________________
>> R-sig-Geo mailing list
>> R-sig-Geo at r-project.org
>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>
>
--
Roger Bivand
Department of Economics, Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; fax +47 55 95 91 00
e-mail: Roger.Bivand at nhh.no
http://orcid.org/0000-0003-2392-6140
https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en
http://depsy.org/person/434412
More information about the R-sig-Geo
mailing list