------------------------------------------------------------------------------- help forconcindexi(Amadou Bassirou DIALLO: AFTPM, The World Bank and CERDI, Univ. of Auvergne) -------------------------------------------------------------------------------

Estimation of the Concentration Index based on Kakwani and Wagstaff covariance> formulae.

concindexi[varlist] [if] [in] [weight] [,welfarevar(varname)format(format)curveconvenientclean}where :

welfarevaris the welfare variable - not optional - ,

formatis the format type used to display results,

cleanis to erase matrices and scalars created by the program,

curveis to graph lorenz curve for each indicator,

convenientis to use in addition the convenient regression method to compute the concentration index.

Description

concindexicomputes the concentration index on individual (micro) data. See work by Wagstaff and Kakwani.

FormulasThe concentration index is computed as:

C = 2 cov(yi,Ri) / µ

yi is the individual i's indicator variable (e.g. health status),

µ its mean

Ri his fractional rank in the socioeconomic distribution

Standard errors of C are obtained by a "covariance" or "formula" method:

1 1 2 2 Var(C) = - [ - sum (a ) - (1 + C) ] n n

where :

yi a = - ( 2 Ri - 1 - C) + 2 - qi-1 - qi µ

and :

1 qi = - sum(yi) µn

is the ordinate of the concentration curve L(p), and q0 = 0.

Examples

. concindexi has_water has_elec, welf(quint)

. concindexi has_water has_elec, welf(quint) cu cl)

. concindexi has_water [aw=weight], we(quint) co by(urbrur)

. concindexi var1 var2 [aw=weight], we(quint) f(%9.2f)

Saved ResultsConcentration indices are saved in matrice r(CII).

AuthorAmadou Bassirou DIALLO, AFTPM, The World Bank -and- CERDI, Univ. of Auvergne (France).

Email: adiallo5@worldbank.org, adiallo5@gmail.com

NoteThis program has been initially developped to use the Demographic and Health Surveys (DHS).

Also seeOnline: help for concindexg, ineqdeco, inequal, povdeco, ineqerr if installed.

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