16
Stata Technical Bulletin
STB-48
Options
bygroup (.groupaar^) requests poverty decompositions by population subgroup, with subgroup membership summarized by
groupvar.
Saved results
S-FGTO FGT(0), defined above
S-FGTl FGT(1), defined above
S-FGT2 FGT(2), defined above
Example
Let consider first the case in which there is a common poverty line, taken for illustration to be equal to half average
needs-adjusted income, and decompose poverty by tenure subgroups.
. local z = .5*'meanz
. povdeco eybhc [fw=wgt], pl('zz) by(tenure)
Warning: eybhc has 20 values < 0. Used in calculations
Total number of observations = 6468
Weighted total no. of observations = 55851705
Number of observations poor = 1327
Weighted no. of obs poor = 11336320
Mean of eybhc amongst the poor = 86.711
Mean of poverty gaps (poverty line - eybhc) amongst the poor = 29.798
Foster-Greer-Thorbecke poverty indices, FGT(a)
----------+-----------------------------------
All obs I a=0 a=l a=2
----------+-----------------------------------
I 0.20297 0.05191 0.02387
----------+-----------------------------------
FGT(O) : headcount ratio (proportion poor)
FGT(I): average normalised poverty gap
FGT(2): average squared normalised poverty gap
Decompositions by subgroup
Summary statistics for subgroup к = !,...,K
|
----------+— Tenure of I |
Pop. share |
Mean |
Mean I poor |
— Mean gap I poor |
|
Social r I |
0.22852 |
139.30740 |
93.30663 |
— 23.20227 |
|
Other re I |
0.07194 |
214.48389 |
80.45238 |
36.05652 |
|
Owned:mo I |
0.50169 |
278.40619 |
74.83694 |
41.67195 |
|
Owned: ou I |
0.19785 |
232.90508 |
84.24892 |
32.25999 |
Subgroup FGT index estimates, FGT(a)
|
— Tenure of |
-+— I |
a=0 |
a=l |
— a=2 |
|
— Social r |
I |
0.45587 |
0.09078 |
0.03180 |
|
Other re |
I |
0.22032 |
0.06818 |
0.03938 |
|
Owned:mo |
I |
0.08128 |
0.02907 |
0.01686 |
|
Owned: ou |
I |
0.21313 |
0.05901 |
0.02686 |
Subgroup poverty zsharez, S_k = v_k.FGT_k(a)/FGT(a)
|
— Tenure of |
-+— I |
a=0 |
a=l |
— a=2 |
|
— Social r |
I |
0.51326 |
0.39964 |
0.30439 |
|
Other re |
I |
0.07809 |
0.09449 |
0.11868 |
|
Owned:mo |
I |
0.20090 |
0.28095 |
0.35433 |
|
Owned: ou |
I |
0.20776 |
0.22492 |
0.22260 |