help spmon
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Title

spmon - Creates spatial effect variable for monadic data


Syntax


        spmon lagvar [if] [in], weightvar(varname) i(varname) k(varname)
                 [options]


    options               Description
    -------------------------------------------------------------------------
      time(varname)       contains the numeric time variable
      reverse_W           revert the direction of weight variable
      norowst             spatial effect variable not row-standardized
      nomerge             no automatic merge of spatial effect variable into
                            original dataset
      sename(name)        name to be given to created spatial effect variable
      labelname(name)     name of label given to spatial effect variable
      filename(name)      name of file to which spatial effect variable saved
    -------------------------------------------------------------------------


Description

    spmon generates a spatial effect variable for analysis of spatial
    dependence in monadic data, i.e. where the estimation dataset consists of
    individual units (as in the vast majority of datasets used in the social
    sciences), rather than of dyads (pairs of units).  It can create spatial
    effect variables for spatial lag, spatial-x and spatial error models.
    See Neumayer and Plümper (2010) for a discussion of the difference
    between monadic and dyadic data.  See Plümper and Neumayer (2010) for a
    discussion of model specification in the analysis of spatial dependence.
    Users must have mmerge.ado already installed. If not, type net search
    mmerge.ado into the editor and install.

Additional information

    See http://personal.lse.ac.uk/neumayer/spmon.htm.


Arguments

        +------+
    ----+ Main +-------------------------------------------------------------

    lagvar is the variable to be spatially lagged. It is the dependent
        variable of unit k in spatial lag models, a selected independent
        variable of unit k in spatial-x models and a saved regression
        residual in spatial error models.  It must be the same for all dyads
        of a specific unit k with all combinations of unit i (for any given
        time period).

    weightvar(varname) is the weighting or connectivity variable. It connects
        unit i with unit k. It must be numeric and must not contain negative
        values. It may or may not be directed.

    i(varname) is the identifying variable of unit i. It can be a numeric or
        string variable.

    k(varname) is the identifying variable of unit k. It can be a numeric or
        string variable.


Options

        +------+
    ----+ Main +-------------------------------------------------------------

    time(varname) is an optional argument. If users wish to generate a
        time-varying spatial effect variable, then the numeric time variable
        must be stated here.

    reverse_W requests that the direction of the connectivity variable is to
        be reversed. This only matters if the weighting variable
        weightvar(varname) is a directed variable. In the default option,
        weightvar(varname) represents connectivity from unit i to other units
        k. reverse_W requests that the direction of this weighting variable
        is to be reversed, such that a virtually transformed weighting matrix
        instead represents connectivity from other units k to unit i.

    norowst requests that the generated spatial effect variable is not
        row-standardized.  See Plümper and Neumayer (2010) for an explanation
        and discussion of row-standardization.  Row-standardization is the
        default option.

    nomerge requests that the generated spatial effect variable is not
        automatically merged into the original data set.

    sename(name) names the generated spatial effect variable. In the default
        option, if the weighting matrix is row-standardized, then the
        generated spatial effect variable is called SE_var_monadic_rowst. If
        the weighting matrix is not row-standardized, then the spatial effect
        variable is called SE_var_monadic_norowst.  Any previously existing
        variable with the same name will be replaced.

    labelname(name) names the label of the generated spatial effect variable.
        The default label given is "Monadic spatial effect variable".

    filename(name) requests that a dataset containing the generated spatial
        effect variable is saved in the current working directory under the
        defined name. In the default option, if the weighting matrix is
        row-standardized, then a file is saved in the current working
        directory called SE_file_monadic_rowst.  If the weighting matrix is
        not row-standardized, then the saved file is called
        SE_file_monadic_norowst.  Any previously existing file with the same
        name will be replaced.

References

    Neumayer, Eric and Plümper, Thomas. 2010. Spatial Effects in Dyadic Data.
    International Organization 64 (1), pp. 145-165.

    Plümper, Thomas and Eric Neumayer. 2010. Model Specification in the
    Analysis of Spatial Dependence. European Journal of Political Research 49
    (3), pp. 418-442.

Examples

    . spmon y, w(contiguity) i(country_i) k(country_k) sename(se_monadic)
        filename(se_monadic_file)

    . spmon y, w(exports) i(country_i) k(country_k) time(year) revert_W
        norowst

    . spmon y, w(exports) i(country_i) k(country_k) time(year) norowst


Authors

    Eric Neumayer
    Department of Geography and Environment
    London School of Economics and Political Science (LSE)
    London WC2A 2AE, UK
    e.neumayer@lse.ac.uk
    http://personal.lse.ac.uk/neumayer

    Thomas Plümper
    Department of Government
    University of Essex
    Wivenhoe Park
    Colchester CO4 3SQ, UK
    tpluem@essex.ac.uk
    http://www.polsci.org/pluemper/