10
Stata Technical Bulletin
STB-48
Options
bygroup ggroppaar) requests inequality decompositions by population subgroup, with subgroup membership summarized by
groupvar.
w requests calculation of equally-distributed-equivalent incomes and welfare indices in addition to the inequality index calculations.
summ requests presentation of summary, detail output for varname.
Saved results
S_9010, S_7525 Percentile ratios p90/p10, p75/p25
S-iml, S_i0, S_il, S_i2 GE(a),fora=-1,0,1,2
S_ahalf, S_il, S_a2 A(e), for e = 0.5, 1, 2
Example
Standard output from ineqdeco with only the welfare index option chosen is as follows.
. ineqdeco eybhc [fw=wgt], w
Warning: eybhc has 20 values < 0. Not used in calculations
Percentile ratios for distribution of eybhc: all valid obs.
—
p90∕pl0 p90∕p50 pl0∕p50 p75∕p25 p75∕p50 p25∕p50
—
4.336 2.063 0.476 2.249 1.474 0.655
Generalized Entropy indices GE(a), where a = income difference
sensitivity parameter, and Gini coefficient
----------+-----------------------------------------------------------
All obs I GE(-1) GE(O) GE(I) GE(2) Gini
----------+-----------------------------------------------------------
I 3.66972 0.19386 0.20530 0.36167 0.33263
----------+-----------------------------------------------------------
Atkinson indices, A(e), where e > 0 is the inequality aversion parameter
----------+-----------------------------------
All obs I A(0.5) A(I) A(2)
----------+-----------------------------------
I 0.09294 0.17622 0.88009
----------+-----------------------------------
Equally-distributed-equivalent incomes, Yede(e)
----------+-----------------------------------
All obs I Yede(0.5) Yede(I) Yede(2)
----------+-----------------------------------
I 212.04836 192.57941 28.03261
----------+-----------------------------------
Social welfare indices, W(e), and Sen's welfare index
----------+-----------------------------------------------------------
All obs I W(0.5) W(I) W(2) mean*(l-Gini)
----------+-----------------------------------------------------------
I 29.12376 5.26051 -0.03567 156.01453
----------+-----------------------------------------------------------
We can examine differences in inequality by tenure group using the command
. ineqdeco eybhc [fw=wgt], by(tenure)
Warning: eybhc has 20 values < 0. Not used in calculations
Percentile ratios for distribution of eybhc: all valid obs.
—
p90∕pl0 p90∕p50 pl0∕p50 p75∕p25 p75∕p50 p25∕p50
—
4.336 2.063 0.476 2.249 1.474 0.655
Generalized Entropy indices GE(a), where a = income difference
sensitivity parameter, and Gini coefficient
----------+-----------------------------------------------------------
All obs I GE(-1) GE(O) GE(I) GE(2) Gini
----------+-----------------------------------------------------------
I 3.66972 0.19386 0.20530 0.36167 0.33263
----------+-----------------------------------------------------------