{smcl}
{* December 2008}{...}
{hline}
{cmd:help for anketest} 
{hline}

{title:Title}

{p 2 8 2}
{bf:anketest} ---Performs diagnostic tests for spatial autocorrelation in the residuals from OLS, SAR, IV, and IV-SAR models

{marker contents}{dlgtab: Table of Contents}
{p 2 16 2}

{p 2}{help anketest##syntax:Syntax}{p_end}
{p 2}{help anketest##description:General description}{p_end}
{p 2}{help anketest##options:Description of the options}{p_end}
{p 2}{help anketest##remark:Important remarks}{p_end}
{p 2}{help anketest##examples:Examples}{p_end}
{p 2}{help anketest##refs:References}{p_end}
{p 2}{help anketest##cita:Citation}{p_end}
{p 2}{help anketest##author:Author information}{p_end}
{hline}

{marker syntax}{title:Syntax}

{phang}
{cmd: anketest,} {opt w:name(wght_name)} {opt wf:rom(Stata|Mata)} {opt model(ols|sar|iv|iv-sar)} [{opt favor(speed|space)}]

{synoptset 33 tabbed}
{synopthdr}
{synoptline}
{syntab:Options}   
     
{synopt :{opt w:name(wght_name)}}indicate the name of the spatial weights matrix to be used{p_end}

{synopt :{opt wf:rom(Stata|Mata)}}indicate the source of the spatial weights matrix{p_end}

{synopt :{opt model(ols|sar|iv|iv-sar)}}indicate the estimated model{p_end}

{synopt :{opt favor(speed|space)}}favor speed or space{p_end}


{synoptline}
{p2colreset}{...}

{marker description}{dlgtab:Description}

{pstd}{cmd:anketest} carries out diagnostic tests for spatial autocorrelation in the residuals from Ordinary Least Squares (OLS), 
spatial autoregressive (SAR), and instrumental variable regressions with or without a spatially lagged dependent variable (IV-SAR or IV). 
A spatial weights matrix, which may exist as a Stata matrix loaded in memory or as a Mata file located in the working directory, 
is required.{p_end} 

{pmore}{cmd:anketest} requires Stata 9.2 or higher. 


{marker options}{dlgtab:Options}

{phang}
{opt wname(wght_name)} specifies the name of the spatial weights matrix to be used.

{phang} 
{opt wfrom}{cmd:(}{help matrix:Stata} | {help mf_fopen##remarks5:Mata}{cmd:)} indicates whether the spatial weights matrix is a Stata matrix 
loaded in memory or a Mata file located in the working directory. If the spatial weights had been created using {help spwmatrix}, it should 
exist as a Stata matrix or as a Mata file.

{phang}
{opt model(ols|sar|iv|iv-sar)} indicates the model for which the residuals need to be tested. Specifying {opt model(ols)} implies a model 
estimated using the {help regress} command. {opt model(sar)} implies a model containing a spatially lagged dependent variable estimated by 
spatial two-stage least squares (2SLS) using the Stata's official command {help ivregress}  or the user-written command {help ivreg29}. 
The {it:SAR} model may have also been estimated by maximum likelihood using the user-written command {help spmlreg}. {opt model(iv)} 
suggests a model estimated with (non-spatial) endogenous regressors, but without a spatially lagged dependent variable. {opt model(iv-sar)} 
indicates a model containing both (non-spatial) endogenous variables and a spatially lagged dependent variable. The command {help ivregress}, 
or {help ivreg29} must have been used to estimate the {it:iv} model by 2SLS and the {it:iv-sar} model by spatial 2SLS. For model estimation 
by spatial 2SLS in {cmd:Stata} see {help splagvar}. 

{phang}
{opt favor(speed|space)} instructs {cmd:anketest} to favor speed or space when calculating the test statistics.
{opt favor(speed)} is the default. This option provides a tradeoff between speed and memory use. See {help mata_set:[M-3] mata set}.

{marker remark}{dlgtab:Important remarks}

{phang}
When testing the residuals from a spatial lag model estimated by maximum likelihood (ML), two spatial weights, 
which may be the same or different, are required, one for each spatial dependence structure (lag and error). If the name of the spatial weights 
matrix supplied to {help spmlreg} with {opt weights()} for the estimation of the spatial lag model is the same as that of the spatial weights 
matrix specified with {opt wname()}, then that spatial weights matrix will be used for both structures. Otherwise, {cmd:anketest} will use the 
spatial weights matrix supplied to {help spmlreg} with {opt weights()} for the lag structure and the spatial weights matrix specified with 
{opt wname()} for the error structure.



{marker examples}{dlgtab:Examples}

{phang}
1) Test for spatial autocorrelation in the residuals from an OLS model 

{pmore}{cmd:. anketest, wname(mywght) wfrom(Mata) model(ols)}

{synoptline}

{phang}
2) Test for spatial autocorrelation in the residuals from an IV model

{pmore}{cmd:. anketest, wname(mywght) wfrom(Mata) model(iv)}

{synoptline}

{phang}
3) Test for spatial autocorrelation in the residuals from a model containing non-spatial endogenous right-handside variables and a spatially lagged dependent variable

{pmore}{cmd:. anketest, wname(mywght) wfrom(Mata) model(iv-sar)}


{marker refs}{title:References}

{bf:Anselin, L}., 2007. "Spatial Econometrics." In T. C. Mills and K. Patterson (Eds). {it:Palgrave Handbook of Econometrics. Vol 1, Econometric Theory}. 
New York: Palgrave MacMillan, pp. 901-969.

{bf:Anselin, L}., 2001. {it:Spatial Econometrics}. In Baltagi, B. (Ed). {it:A Companion to Theoretical Econometrics}. 
Basil Blackwell: Oxford, UK, 310-330.

{bf:Anselin, L}., 1988. {it:Spatial Econometrics: Methods and Models}. Kluwer Academic Publishers, Dordrecht, The Netherlands.

{bf:Anselin, L., Kelejian, H. H}., 1997. Testing for Spatial Error Autocorrelation in the Presence of Endogenous Regressors. 
{it:International Regional Science Review} 20, 153-182.


{marker cita}{title:Citation}

Users should please cite anktest as:

{bf:Jeanty, P.W.}, 2010. anketest: Stata module to perform diagnostic tests for spatial autocorrelation in the residuals from OLS, SAR, IV, and IV-SAR models. 
Available from ideas.repec.org/c/boc/bocode/s457113.html. 


{marker author}{title:Author}

{p 4 4 2}{hi: P. Wilner Jeanty}, Dept. of Agricultural, Environmental, and Development Economics, The Ohio State University{break}
	   
{p 4 4 2}Email to {browse "mailto:jeanty.1@osu.edu":jeanty.1@osu.edu} for any comments or suggestions.


{title:Also see}

{p 4 13 2}Online: {helpb spatdiag} (if installed)