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Measures of inequality (revised)

inequal7varlist[weight] [ifexp] [inrange] [,format(%fmt)returnscalars]

aweights andfweights are allowed; see help weights.

Description

inequal7computes a series of inequality measures of the variables invarlist. It is a revised and upgraded version ofinequalpublished by Edward Whitehouse in STB-23.inequal7also supersedes the previously releasedinequal2.Up to 5 variables can be specified in

varlist.The inequality measures computed are: the "relative mean deviation", the "coefficient of variation", the "standard deviation of logs", the"Gini index", the "Mehran index", the "Piesch index", the "Kakwani index", "Theil entropy index", the "mean log deviation" and the "generalised entropy measure" with sensitivity parameters -1 and 2 [see, e.g., Cowell [1995] for a definition of these measures].

Seven changes have been made compared to

inequal: - Inclusion of the "generalised entropy measure" with sensitivity parameters -1 and 2; - The procedure acceptsaweights; - The procedure computes inequality measures for up to 5 variables; - The procedure returns results in r() format (and in global macros); - Ranks are computed in a modified way with weighted data, so that results obtained with grouped data are consistent with individual data; - Output appearence conforms to Stata 7 standards; - Control over the display format is given to the user with a standardformat(%fmt)option.

Options

format(%fmt)specifies the format to be used to display the estimated inequality indices. The default is to use a%6.5fformat.

returnscalarsrequests that estimated indices be returned in r() scalars (instead of r() locals).

Saved ResultsFor historical reasons,

inequal7returns results in r() locals and in global macros. However, to allow usinginequal7with thebootstraporjkknifecommands, results can be saved in r() scalars by specifying thereturnscalarsoption.[Important notice: When multiple variables are entered in

varlist, returned results are the inequality measures of thelastvariable listed.]r(rmd) and S_1 contain the "relative mean deviation" r(cov) and S_2 contain the "coefficient of variation" r(sdl) and S_3 contain the "standard deviation of logs" r(gini) and S_4 contain the "Gini coefficient"' r(mehran) and S_5 contain the "Mehran index" r(piesch) and S_6 contain the "Piesch index" r(kakwani) and S_7 contain the "Kakwani index" r(theil) and S_8 contain the "Theil index (or generalised entropy measure with sensitivity parameter 1)" r(mld) and S_9 contain the "Mean Log Deviation (or generalised entropy measure with sensitivity parameter 0)" r(ge_1) and S_10 contain the "Generalised entropy measure with sensitivity parameter -1" r(ge2) and S_11 contain the "Generalised entropy measure with sensitivity parameter 2"

Acknowledgements

inequal7is an upgrade ofinequalpublished in Stata Technical Bulletin 23. Edward Whitehouse, the original author, is therefore the key contributor toinequal7. Useful comments and testing by Stephen Jenkins are gratefully acknowledged. Thanks also to A. Peichl and A. Paulus for detailed bug reports.

ReferencesCoulter Ph. (1989), Measuring Inequality -A Methodological Handbook-, Westview Press USA.

Cowell, F.A. (1995). Measuring Inequality (second edition). Prentice-Hall/Harvester-Wheatsheaf, Hemel Hempstead.

Whitehouse, E. (1994). sg30:Measures of inequality in Stata. Stata Technical Bulletin 23.

AuthorPhilippe VAN KERM <philippe.vankerm@ceps.lu> CEPS/INSTEAD Differdange, G.-D. Luxembourg

Also seeManual:

[R] lorenzSTB:sg30 (STB-23)On-line: help for inequal (if installed), ineqdeco (if installed), ineqerr (if installed)