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help for skdecomp                                              Bernardo Atuesta
                                                             Joao Pedro Azevedo
                                                              Andres Castanedas
                                                              Viviane Sanfelice
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Shapley value of growth, price, and distribution components of on changes in po
> verty indicators

        skdecomp welfarevar [weight] [if exp] [in exp] , by(varname)
                 varpl(varname) [ indicator(string) mpl(numlist) idpl(varname)
                 ]

    fweights and aweights are allowed; see help weights. See help weight.


Description

    skdecomp implements the shapley value of Kolenikov and Shorrocks (2003)
    decomposition of changes in a welfare indicator into growth, distribution
    and price.


Where

    welfarevar is the welfare aggregate variable.

    by is the comparison variable. It must take two categorical values and is
    usually defines as two points in time or two geographic locations, which
    the difference of the indicator is being decomposed.

    varpl(varname) poverty line variable.


Options

    indicator(string) poverty indicators. fgt0, fgt1, fgt2 are the currently
    supported options. fgt0 is the indicator default.

    mpl(numlist) allow to calculate the poverty indicators by range using
    multiples of the poverty line.

    idpl(varname) to switch the poverty line in case the poverty line is not
    constant to all the observation in one categorical of by. For instance,
    there are different poverty lines to urban and rural areas.


Saved Results

skdecomp returns results in r() format. 
By typing return list, the following results are reported:

    Matrices       
      r(b)                average effect by factors and the total change on
                            the poverty indicator.
      r(shapley)          besides the average effect, returns the
                            contribution of each paths.
      r(poverty)           returns the value of the indicator by categorical
                            value of by.

    Obs: On the reported matrices

    Indicator label: 0 - FGT(0); 1 - FGT(1); 2 - FGT(2).

    Effect label: 1 represents the growth; 2 distribtuion; 3 line and 4 the
    total change in percentage points on the indicator.

    Line label (if mpl specified): 1 represents the first multiple; 2 the
    second, and so on. The last indicates the range from the last multiple
    and the maximun value.


Examples

        . skdecomp income, by(year) varpl(pline)

        . skdecomp income, by(year) varpl(pline) idpl(region)

        . skdecomp income, by(year) varpl(pline) in(fgt0 fgt1 fgt2)

        . skdecomp income, by(year) varpl(pline) mpl(1 2.5 6)



      (click to run the example below)
        
        
        {Original SK decomposition - welfare and poverty line variable in
            nominal terms}
        
        . skdecomp ipcf [w=pondera], by(ano) varpl(lp_4usd) ///
        . in(fgt0 fgt1 fgt2) 
                


References

    Shorrocks, A.; Kolenikov, S. A Decomposition Analysis of Regional Poverty
    in Russia, Discussion Paper No. 2003/74 United Nations University, 2003.

    Shorrocks, A. F. Decomposition procedures for distributional analysis: a
    unified framework based on the Shapley value. Journal of Economic
    Inequality, 2012.

    World Bank (2011) On The Edge Of Uncertainty: Poverty Reduction in Latin
    America and the Caribbean during the Great Recession and Beyond. LAC
    Poverty and Labor Brief. World Bank: Washington DC.   (link to
    publication)

Authors

    Bernardo Atuesta,
    Joao Pedro Azevedo, jazevedo@worldbank.org
    Andres Castanedas, acastanedaa@worldbank.org
    Viviane Sanfelice, vsanfelice@worldbank.org


Acknowledgements
    
    This program was developed by the  LAC Team for Statistical Development
    (2012), in the Latin American and Caribbean Poverty Reduction and
    Economic Managment Group of the World Bank.


Also see

  Online:  help for gidecomposition; apoverty; ainequal; wbopendata; adecomp;
    mpovline; drdecomp (if installed)