Hhi

[Paris Rira]

Dear Profs and Colleagues,

The question is" The demographic index is built from the intersection of gender and age quartiles".
The Herfinadl index should be by firm i (firm id NPC_FIC) and time t (2010-2019)

* Example generated by -dataex-. For more info, type help dataex
clear
input double(year NPC_FIC sexo) float age_group
2010 500000001 2 4
2010 500000001 2 3
2010 500000001 2 3
2010 500000002 1 2
2010 500000002 1 4
2010 500000002 1 4
2010 500000002 1 2
2010 500000033 2 3
2010 500000033 1 2
2010 500000050 1 2
2010 500000050 1 3
2010 500000083 2 1
2010 500000104 2 4
2010 500000119 1 2
2010 500000119 1 3
2010 500000119 1 2
2010 500000119 1 2
2010 500000119 1 2
2010 500000119 2 3
2010 500000119 2 2
2010 500000119 2 2
2010 500000121 1 3
2010 500000121 1 4
2010 500000156 1 1
2010 500000156 1 3
2010 500000157 2 3
2010 500000157 2 1
2010 500000157 2 2
2010 500000157 2 3
2010 500000165 1 3
2010 500000165 1 2
2010 500000180 1 2
2010 500000198 2 2
2010 500000198 2 3
2010 500000201 2 3
2010 500000204 1 3
2010 500000212 1 3
2010 500000215 2 2
2010 500000215 2 2
2010 500000215 2 1
2010 500000215 2 3
2010 500000240 2 3
2010 500000240 1 3
2010 500000276 1 1
2010 500000279 2 1
2010 500000284 1 3
2010 500000284 1 4
2010 500000284 1 3
2010 500000284 2 2
2010 500000305 2 2
2010 500000324 2 1
2010 500000341 1 1
2010 500000341 1 2
2010 500000346 1 1
2010 500000346 1 1
2010 500000346 1 2
2010 500000346 1 1
2010 500000346 2 1
2010 500000376 2 3
2010 500000376 2 4
2010 500000376 2 4
2010 500000376 2 3
2010 500000376 2 4
2010 500000376 2 3
2010 500000395 1 3
2010 500000395 2 1
2010 500000395 2 3
2010 500000395 2 1
2010 500000395 2 1
2010 500000465 2 3
2010 500000465 2 2
2010 500000465 2 3
2010 500000470 2 1
2010 500000470 2 2
2010 500000478 1 1
2010 500000525 2 2
2010 500000543 2 4
2010 500000543 2 4
2010 500000565 2 2
2010 500000583 2 4
2010 500000583 2 3
2010 500000600 2 4
2010 500000600 2 4
2010 500000633 1 2
2010 500000633 1 2
2010 500000675 2 4
2010 500000709 2 4
2010 500000748 2 2
2010 500000757 2 3
2010 500000761 2 3
2010 500000761 2 2
2010 500000761 2 3
2010 500000761 2 2
2010 500000765 1 4
2010 500000765 1 3
2010 500000766 1 3
2010 500000766 1 3
2010 500000774 1 3
2010 500000791 1 2
2010 500000791 1 1
end
label values sexo sexo
label def sexo 1 "Homem", modify
label def sexo 2 "Mulher", modify
. tab age_group

  age_group |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |  5,268,361       20.39       20.39
          2 |  8,205,795       31.76       52.15
          3 |  7,745,231       29.98       82.13
          4 |  4,616,770       17.87      100.00
------------+-----------------------------------
      Total | 25,836,157      100.00

. tab sexo

       Sexo |      Freq.     Percent        Cum.
------------+-----------------------------------
      Homem | 13,806,906       53.44       53.44
     Mulher | 12,029,251       46.56      100.00
------------+-----------------------------------
      Total | 25,836,157      100.00

sexo is gender. I am confused about how to make the intersection of gender and age quartiles and make HHI.
Any help is appreciated.
cheers,
Paris.