Dear list users,


I am working on a spatial SUR model which consists of t=8 time periods,
N=26 regions, G=3 equations for each sector. I have some troubles and I
really appreciate if you could help me on this.


First, I run the convergence model without taking the time dimension into
account (with the consideration of only the initial and final years) and
estimate a spatial SUR model. Using feasible generalized spatial three
stage least squares, I have the following code, in short:


surform_1 <- formula(growthagr ~ log(eagr04)+log(eind04)+log(eser04))

surform_2 <- formula(growthind ~ log(eagr04)+log(eind04)+log(eser04))

surform_3 <- formula(growthser ~ log(eagr04)+log(eind04)+log(eser04))

surform <-list(Agr=surform_1, Ind=surform_2, Serv=surform_3)

listw <- nb2listw(queen_nb, style="W")

surlag.gm <-spsegm(surform, data=surdata_LAEA, panel=FALSE, w=listw,
lags=list(c(TRUE,FALSE,FALSE), c(FALSE,TRUE,FALSE), c(FALSE,FALSE,TRUE)),
errors=list(FALSE,FALSE,FALSE), method="spatialsim")


However, this gives a simultaneous equations solution. I know the package
“spse” is proposing also a SUR solution, but I could not find an
alternative way of estimating, other than “spatialsim”. How can I convert
this into a SUR framework with only contemporaneous correlation in
disturbances?


The problem persists when I run the regression by introducing the data in
panel form, but estimate a SUR spatial cross-sectional model like this:


surlag.gm <-spsegm(surform, data=panelsurdata, panel=TRUE, index="nuts2",
listw, lag=list(TRUE,TRUE,TRUE), errors=list(FALSE,FALSE,FALSE))


This time I get the error: “number of equations and time period in the data
should correspond”. However each equation in the SUR does not correspond to
time periods but sectors in my case (unlike the original Anselin(1988)
model but more like Wang and Kockelman(2007) model).


Second, I run this model in a panel SUR spatial framework (with random
effects). There is no problem with the model including only spatial error
components. But when I add spatial lag term,


surrandlag.gm <-spsepgm(surform, data=panelsurdata, index="nuts2", listw,
model="random", lag=list(TRUE,TRUE,TRUE),
spatial.error=list(FALSE,FALSE,FALSE), moments="fullweights", endog=NULL
,method="g2sls")


I got an error like this:

“Error in solve.default(crossprod(Zp)) : 'a' is 0-diml”


I would be really happy if you could give any idea about solving these
issues.

Thanks in advance,

Best regards,

Pelin Akcagun

Middle East Technical University

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